diff --git a/backend/src/main/java/th/co/glr/hr/deposit/DepositNoticeController.java b/backend/src/main/java/th/co/glr/hr/deposit/DepositNoticeController.java
index 34756b3b1..10819741e 100644
--- a/backend/src/main/java/th/co/glr/hr/deposit/DepositNoticeController.java
+++ b/backend/src/main/java/th/co/glr/hr/deposit/DepositNoticeController.java
@@ -98,9 +98,11 @@ ResponseEntity<byte[]> preview(@PathVariable long docId, HttpSession session) {
 
     // Issue (assign doc number + transition ticket)
     @PostMapping("/deposit-notices/{docId}/issue")
-    Map<String, DepositNoticeDto> issue(@PathVariable long docId, HttpSession session) {
+    Map<String, DepositNoticeDto> issue(@PathVariable long docId,
+                                        @RequestBody(required = false) DepositNoticeIssueRequest body,
+                                        HttpSession session) {
         UserPrincipal user = sessions.requireUser(session);
-        return Map.of("depositNotice", service.issue(docId, user));
+        return Map.of("depositNotice", service.issue(docId, body == null ? null : body.expectedUpdatedAt(), user));
     }
 
     // File download
diff --git a/backend/src/main/java/th/co/glr/hr/deposit/DepositNoticeDraftRequest.java b/backend/src/main/java/th/co/glr/hr/deposit/DepositNoticeDraftRequest.java
index 336c68813..dd0561ece 100644
--- a/backend/src/main/java/th/co/glr/hr/deposit/DepositNoticeDraftRequest.java
+++ b/backend/src/main/java/th/co/glr/hr/deposit/DepositNoticeDraftRequest.java
@@ -5,6 +5,7 @@
 import jakarta.validation.constraints.DecimalMin;
 import jakarta.validation.constraints.Size;
 import java.math.BigDecimal;
+import java.time.OffsetDateTime;
 import java.util.List;
 
 public record DepositNoticeDraftRequest(
@@ -13,7 +14,17 @@ public record DepositNoticeDraftRequest(
     @Size(max = 255) String customerAddress,
     @Size(max = 255) String projectName,
     @Size(max = 255) String reference,
-    @DecimalMin("0") @DecimalMax("1") BigDecimal depositPercent,
+    @DecimalMin(value = "0", inclusive = false, message = "เปอร์เซ็นต์มัดจำต้องมากกว่า 0")
+    @DecimalMax(value = "1", message = "เปอร์เซ็นต์มัดจำต้องไม่เกิน 100") BigDecimal depositPercent,
     List<String> notes,
-    @Valid List<DepositNoticeItemRequest> items
-) {}
+    @Valid List<DepositNoticeItemRequest> items,
+    // The draft's updatedAt as this client last read it. null skips the stale-save check (older clients).
+    OffsetDateTime expectedUpdatedAt
+) {
+    /** Without a stamp: creation and the server-side callers. */
+    public DepositNoticeDraftRequest(String customerName, String customerTaxId, String customerAddress,
+                                     String projectName, String reference, BigDecimal depositPercent,
+                                     List<String> notes, List<DepositNoticeItemRequest> items) {
+        this(customerName, customerTaxId, customerAddress, projectName, reference, depositPercent, notes, items, null);
+    }
+}
diff --git a/backend/src/main/java/th/co/glr/hr/deposit/DepositNoticeIssueRequest.java b/backend/src/main/java/th/co/glr/hr/deposit/DepositNoticeIssueRequest.java
new file mode 100644
index 000000000..681ef084a
--- /dev/null
+++ b/backend/src/main/java/th/co/glr/hr/deposit/DepositNoticeIssueRequest.java
@@ -0,0 +1,6 @@
+package th.co.glr.hr.deposit;
+
+import java.time.OffsetDateTime;
+
+/** Optional body of the issue call: the draft's updatedAt as the caller last read it (null skips the check). */
+public record DepositNoticeIssueRequest(OffsetDateTime expectedUpdatedAt) {}
diff --git a/backend/src/main/java/th/co/glr/hr/deposit/DepositNoticeRepository.java b/backend/src/main/java/th/co/glr/hr/deposit/DepositNoticeRepository.java
index 271ca9750..634932892 100644
--- a/backend/src/main/java/th/co/glr/hr/deposit/DepositNoticeRepository.java
+++ b/backend/src/main/java/th/co/glr/hr/deposit/DepositNoticeRepository.java
@@ -13,6 +13,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
+import org.springframework.http.HttpStatus;
 import org.springframework.jdbc.core.namedparam.MapSqlParameterSource;
 import org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate;
 import org.springframework.jdbc.support.GeneratedKeyHolder;
@@ -23,6 +24,9 @@
 
 @Repository
 public class DepositNoticeRepository {
+    static final String NOT_DRAFT = "ใบแจ้งรับมัดจำนี้ไม่ได้อยู่ในสถานะร่าง (DRAFT)";
+    static final String EDITED_ELSEWHERE = "ใบแจ้งรับมัดจำนี้ถูกแก้ไขโดยผู้ใช้อื่น กรุณาโหลดข้อมูลใหม่แล้วลองอีกครั้ง";
+
     private final NamedParameterJdbcTemplate jdbc;
 
     public DepositNoticeRepository(NamedParameterJdbcTemplate jdbc) {
@@ -199,14 +203,22 @@ public long createDraft(long ticketId, DepositNoticeDraftRequest req, List<Depos
         return docId;
     }
 
+    /**
+     * Saves a DRAFT. Refuses with 409 before touching the lines when the row is no longer DRAFT
+     * (issued after the service read it) or, given {@code req.expectedUpdatedAt()}, someone else
+     * saved it since that stamp. {@code req.depositPercent()} is always set by the service.
+     */
     @Transactional
-    public void update(long docId, DepositNoticeDraftRequest req) {
-        BigDecimal depositPct = req.depositPercent() != null ? req.depositPercent() : new BigDecimal("0.50");
+    public void update(long docId, DepositNoticeDraftRequest req, List<DepositNoticeItemDto> storedItems) {
+        BigDecimal depositPct = req.depositPercent();
         BigDecimal vatPct = new BigDecimal("0.07");
         List<DepositNoticeItemRequest> items = req.items() != null ? req.items() : List.of();
 
-        BigDecimal subtotal = items.stream()
-            .map(it -> it.netUnitPrice().multiply(it.qty()))
+        // No items in the request (null or empty) keeps the stored lines (they are only replaced
+        // below when items are sent), so the subtotal must come from those same stored lines.
+        BigDecimal subtotal = (items.isEmpty()
+                ? storedItems.stream().map(it -> it.netUnitPrice().multiply(it.qty()))
+                : items.stream().map(it -> it.netUnitPrice().multiply(it.qty())))
             .reduce(BigDecimal.ZERO, BigDecimal::add)
             .setScale(2, RoundingMode.HALF_UP);
         BigDecimal deposit = subtotal.multiply(depositPct).setScale(2, RoundingMode.HALF_UP);
@@ -215,7 +227,7 @@ public void update(long docId, DepositNoticeDraftRequest req) {
 
         String[] notesArr = req.notes() != null ? req.notes().toArray(String[]::new) : new String[0];
 
-        jdbc.update("""
+        int rows = jdbc.update("""
             UPDATE sales.deposit_notice SET
                 customer_name    = :customerName,
                 customer_tax_id  = :customerTaxId,
@@ -230,9 +242,11 @@ public void update(long docId, DepositNoticeDraftRequest req) {
                 notes            = :notes,
                 updated_at       = now()
              WHERE deposit_notice_id = :id AND status = 'DRAFT'
+               AND (CAST(:expectedUpdatedAt AS timestamptz) IS NULL OR updated_at = :expectedUpdatedAt)
             """,
             new MapSqlParameterSource()
                 .addValue("id",              docId)
+                .addValue("expectedUpdatedAt", req.expectedUpdatedAt())
                 .addValue("customerName",    req.customerName())
                 .addValue("customerTaxId",   req.customerTaxId())
                 .addValue("customerAddress", req.customerAddress())
@@ -245,6 +259,12 @@ public void update(long docId, DepositNoticeDraftRequest req) {
                 .addValue("totalPayable",    total)
                 .addValue("notes",           notesArr)
         );
+        if (rows == 0) {
+            boolean stillDraft = req.expectedUpdatedAt() != null && !jdbc.queryForList(
+                "SELECT 1 FROM sales.deposit_notice WHERE deposit_notice_id = :id AND status = 'DRAFT'",
+                Map.of("id", docId), Integer.class).isEmpty();
+            throw new th.co.glr.hr.common.ApiException(HttpStatus.CONFLICT, stillDraft ? EDITED_ELSEWHERE : NOT_DRAFT);
+        }
         if (!items.isEmpty()) {
             jdbc.update("DELETE FROM sales.deposit_notice_item WHERE deposit_notice_id = :id", Map.of("id", docId));
             insertItems(docId, items);
@@ -270,8 +290,12 @@ public void update(long docId, DepositNoticeDraftRequest req) {
      *
      * @return the new doc number, or {@link Optional#empty()} if the row was not DRAFT.
      */
-    @Transactional
     public Optional<String> issue(long docId, long actorId, String actorName) {
+        return issue(docId, actorId, actorName, null);
+    }
+
+    @Transactional
+    public Optional<String> issue(long docId, long actorId, String actorName, java.time.OffsetDateTime expectedUpdatedAt) {
         int thaiYear = Year.now().getValue() + 543;
         String docNumber = nextDocNumber("DEPOSIT_NOTICE", thaiYear);
 
@@ -285,21 +309,23 @@ public Optional<String> issue(long docId, long actorId, String actorName) {
                 updated_at     = now()
              WHERE deposit_notice_id = :id
                AND status = 'DRAFT'
+               AND (CAST(:expectedUpdatedAt AS timestamptz) IS NULL OR updated_at = :expectedUpdatedAt)
             """,
-            Map.of("num", docNumber, "actorId", actorId, "actorName", actorName, "id", docId));
+            new MapSqlParameterSource()
+                .addValue("num", docNumber).addValue("actorId", actorId).addValue("actorName", actorName)
+                .addValue("id", docId).addValue("expectedUpdatedAt", expectedUpdatedAt));
 
         if (rows == 0) {
+            // Still a draft with a stamp given => it was saved after the caller read it.
+            boolean editedSince = expectedUpdatedAt != null && !jdbc.queryForList(
+                "SELECT 1 FROM sales.deposit_notice WHERE deposit_notice_id = :id AND status = 'DRAFT'",
+                Map.of("id", docId), Integer.class).isEmpty();
+            if (editedSince) {
+                throw new th.co.glr.hr.common.ApiException(HttpStatus.CONFLICT, EDITED_ELSEWHERE);
+            }
             return Optional.empty();
         }
 
-        // Supersede all older versions for same ticket
-        jdbc.update("""
-            UPDATE sales.deposit_notice SET status = 'SUPERSEDED', updated_at = now()
-             WHERE ticket_id = (SELECT ticket_id FROM sales.deposit_notice WHERE deposit_notice_id = :id)
-               AND deposit_notice_id <> :id
-               AND status = 'ISSUED'
-            """, Map.of("id", docId));
-
         return Optional.of(docNumber);
     }
 
@@ -365,14 +391,23 @@ private void insertItems(long docId, List<DepositNoticeItemRequest> items) {
      * items. Reads the RESOLVED display columns the quotation itself prints
      * ({@code qty}/{@code raw_unit}/{@code unit_price}/{@code final_unit_price}), NOT the legacy
      * {@code requested_*}/{@code approved_unit_price} columns the V2 chain leaves null. The
-     * discount-label wording matches {@link DepositNoticeService#itemsFromQuotation}. */
+     * discount-label wording matches {@link DepositNoticeService#itemsFromQuotation}. An ADJUSTMENT
+     * row is folded into the goods lines, see {@link #foldAdjustments}. */
     public List<DepositNoticeItemRequest> findDealQuotationItems(long quotationId) {
-        return jdbc.query("""
-            SELECT seq, description, qty, raw_unit, unit_price, sales_discount, final_unit_price
+        List<DepositNoticeItemRequest> goods = new java.util.ArrayList<>();
+        BigDecimal[] adjustment = {BigDecimal.ZERO};
+        jdbc.query("""
+            SELECT seq, description, qty, raw_unit, unit_price, sales_discount, final_unit_price, line_type
               FROM sales.quotation_item
              WHERE quotation_id = :quotationId
              ORDER BY seq
-            """, Map.of("quotationId", quotationId), (rs, i) -> {
+            """, Map.of("quotationId", quotationId), rs -> {
+                if ("ADJUSTMENT".equals(rs.getString("line_type"))) {
+                    BigDecimal net = rs.getBigDecimal("final_unit_price");
+                    BigDecimal qty = rs.getBigDecimal("qty");
+                    if (net != null && qty != null) adjustment[0] = adjustment[0].add(net.multiply(qty));
+                    return;
+                }
                 String description = rs.getString("description");
                 if (description == null || description.isBlank()) {
                     description = "รายการสินค้า";
@@ -385,10 +420,49 @@ public List<DepositNoticeItemRequest> findDealQuotationItems(long quotationId) {
                 String discountLabel = discount != null && discount.signum() > 0
                     ? "ส่วนลด " + discount.stripTrailingZeros().toPlainString() + " ต่อหน่วย"
                     : null;
-                return new DepositNoticeItemRequest(
+                goods.add(new DepositNoticeItemRequest(
                     rs.getInt("seq"), description, rs.getBigDecimal("qty"), unit,
-                    rs.getBigDecimal("unit_price"), discountLabel, rs.getBigDecimal("final_unit_price"));
+                    rs.getBigDecimal("unit_price"), discountLabel, rs.getBigDecimal("final_unit_price")));
             });
+        return foldAdjustments(goods, adjustment[0]);
+    }
+
+    /**
+     * Owner rulings 2026-10-23: a DEAL_DIRECT ส่วนลดพิเศษ row (ADJUSTMENT, qty -1) cannot be a
+     * deposit line (the editor's PUT requires qty &gt;= 0), so its amount is spread over the goods
+     * lines in proportion to their amount. "2 decimals for all": each share is HALF_UP to 2 dp and
+     * each line's new net price is 2 dp, with no remainder pushed onto a last line. The notice
+     * totals are the sum of its own stored 2 dp lines ({@code amount = net x qty}), so they can
+     * differ from the quotation's total by under qty x 0.005 baht per line; that is the ruled
+     * outcome, not a bug. A line keeps the quotation's own discount wording, and gains the folded
+     * discount after it only when the fold lowered its price. A free line stays as it is.
+     */
+    static List<DepositNoticeItemRequest> foldAdjustments(List<DepositNoticeItemRequest> goods,
+                                                          BigDecimal adjustment) {
+        BigDecimal goodsTotal = goods.stream().map(it -> it.netUnitPrice().multiply(it.qty()))
+            .reduce(BigDecimal.ZERO, BigDecimal::add);
+        if (adjustment.signum() == 0 || goodsTotal.signum() == 0) {
+            return goods;
+        }
+        List<DepositNoticeItemRequest> folded = new java.util.ArrayList<>();
+        for (DepositNoticeItemRequest it : goods) {
+            BigDecimal amount = it.netUnitPrice().multiply(it.qty());
+            if (amount.signum() == 0) {
+                folded.add(it);
+                continue;
+            }
+            BigDecimal share = adjustment.multiply(amount).divide(goodsTotal, 2, RoundingMode.HALF_UP);
+            BigDecimal net = amount.add(share).divide(it.qty(), 2, RoundingMode.HALF_UP);
+            BigDecimal foldedPerUnit = it.netUnitPrice().subtract(net);
+            String label = it.discountLabel();
+            if (foldedPerUnit.signum() > 0) {
+                String extra = "ส่วนลดพิเศษ " + foldedPerUnit.stripTrailingZeros().toPlainString() + " ต่อหน่วย";
+                label = label == null || label.isBlank() ? extra : label + " + " + extra;
+            }
+            folded.add(new DepositNoticeItemRequest(it.seq(), it.description(), it.qty(), it.unit(), it.unitPrice(),
+                label, net));
+        }
+        return folded;
     }
 
     private List<DepositNoticeItemDto> findItems(long docId) {
diff --git a/backend/src/main/java/th/co/glr/hr/deposit/DepositNoticeService.java b/backend/src/main/java/th/co/glr/hr/deposit/DepositNoticeService.java
index b042d76a1..84afd8e65 100644
--- a/backend/src/main/java/th/co/glr/hr/deposit/DepositNoticeService.java
+++ b/backend/src/main/java/th/co/glr/hr/deposit/DepositNoticeService.java
@@ -103,6 +103,12 @@ public DepositNoticeDto createDraftFromQuotation(long ticketId, DepositNoticeDra
                                                      Integer sourceDepositPercent, UserPrincipal actor) {
         requireRole(actor, SALES_ROLES);
         requireTicketOwner(ticketId, actor);
+        // Owner ruling 2026-10-23: one deposit notice per deal. A new draft would re-seed the % from
+        // the quotation and, once issued, silently supersede the customer's document.
+        docs.findByTicket(ticketId).stream().filter(d -> "ISSUED".equals(d.status())).findFirst().ifPresent(d -> {
+            throw new ApiException(HttpStatus.CONFLICT,
+                "ดีลนี้ออกใบแจ้งรับมัดจำเลขที่ " + d.docNumber() + " แล้ว จึงสร้างฉบับร่างใหม่ไม่ได้");
+        });
         TicketSummaryDto s = requireApprovedTicket(ticketId, actor);
         requireActiveLifecycle(s);
         // Both routes: a deal off the deposit path (a ไม่รับมัดจำ quotation, a waiver, a credit
@@ -149,7 +155,8 @@ public DepositNoticeDto createDraftFromQuotation(long ticketId, DepositNoticeDra
         // req.depositPercent() is never read (DepositNoticeDraftRequest carries it for update's
         // round trip). 0.50 only when the ticket has no live quotation at all (e.g. a manually
         // approved legacy ticket with no quotation chain); see
-        // DepositNoticeRepository#findGoverningQuotation for the pick.
+        // DepositNoticeRepository#findGoverningQuotation for the pick. Sales may change the percent
+        // on the DRAFT afterwards (update, ruling 2026-10-23).
         BigDecimal effectiveDepositPercent = sourceDepositPercent != null
             ? BigDecimal.valueOf(sourceDepositPercent, 2)
             : governing != null ? governing.depositPercent() : new BigDecimal("0.50");
@@ -175,20 +182,29 @@ public static ApiException zeroDepositRefusal(String quotationNumber) {
 
     @Transactional
     public DepositNoticeDto update(long docId, DepositNoticeDraftRequest req, UserPrincipal actor) {
+        requireRole(actor, SALES_ROLES);
         DepositNoticeDto doc = requireDraft(docId);
         requireTicketOwner(doc.ticketId(), actor);
-        // Same owner ruling as createDraft above: the deposit percent is locked to the quotation
-        // at draft-creation time and must NEVER change on update. The frontend no longer offers a
-        // control for it, but a client (or a stale/forged request) sending a different value must
-        // not be trusted either — override whatever req carries with the draft's own already-
-        // stored depositPercent() before persisting.
+        // Owner ruling 2026-10-23: sales may change the deposit percent on a DRAFT (requireDraft
+        // above 409s an issued notice). docs.update recomputes the amount from it. A request
+        // without a percent keeps the draft's own.
+        BigDecimal depositPercent = req.depositPercent() != null ? req.depositPercent() : doc.depositPercent();
+        if (depositPercent.signum() <= 0) {
+            throw new ApiException(HttpStatus.BAD_REQUEST, "เปอร์เซ็นต์มัดจำต้องมากกว่า 0");
+        }
+        // Whole percents only: the document prints the percent rounded (40.5% shows as "41%"). A
+        // percent stored before that rule (0.3330) still saves while it is sent back unchanged;
+        // issue() refuses it until sales picks a whole one.
+        if (depositPercent.compareTo(doc.depositPercent()) != 0 && !isWholePercent(depositPercent)) {
+            throw new ApiException(HttpStatus.BAD_REQUEST, "เปอร์เซ็นต์มัดจำต้องเป็นจำนวนเต็ม");
+        }
         var effective = new DepositNoticeDraftRequest(
             req.customerName(), req.customerTaxId(), req.customerAddress(),
             req.projectName(), req.reference(),
-            doc.depositPercent(),
-            req.notes(), req.items()
+            depositPercent,
+            req.notes(), req.items(), req.expectedUpdatedAt()
         );
-        docs.update(docId, effective);
+        docs.update(docId, effective, doc.items());
         return docs.findById(docId).orElseThrow();
     }
 
@@ -203,11 +219,25 @@ public String preview(long docId, UserPrincipal actor) {
     }
 
     // Issue: assign doc number, freeze document, transition ticket to document_issued
+    // Without a stamp. @Transactional here too: a self-call from this overload would bypass the proxy.
     @Transactional
     public DepositNoticeDto issue(long docId, UserPrincipal actor) {
+        return issue(docId, null, actor);
+    }
+
+    @Transactional
+    public DepositNoticeDto issue(long docId, java.time.OffsetDateTime expectedUpdatedAt, UserPrincipal actor) {
         DepositNoticeDto doc = requireDraft(docId);
         requireRole(actor, SALES_ROLES);
         requireTicketOwner(doc.ticketId(), actor);
+        // The stored percent is what the document prints: outside a whole 1-100 (a 0% ticket-route
+        // draft, a 0.3330 typed before whole percents) it takes no number until fixed on the draft.
+        BigDecimal pct = doc.depositPercent();
+        if (pct.signum() <= 0 || pct.compareTo(BigDecimal.ONE) > 0 || !isWholePercent(pct)) {
+            throw new ApiException(HttpStatus.CONFLICT, "ใบแจ้งรับมัดจำนี้มีเปอร์เซ็นต์มัดจำ "
+                + pct.movePointRight(2).stripTrailingZeros().toPlainString()
+                + "% จึงออกเอกสารไม่ได้ (ต้องเป็นจำนวนเต็ม 1–100)");
+        }
 
         // Issuing the deposit-notice DOCUMENT is the payment-track step: it requires a
         // customer-confirmed quotation and advances paymentStatus, leaving the main
@@ -244,11 +274,21 @@ public DepositNoticeDto issue(long docId, UserPrincipal actor) {
         if (doc.depositAmount() == null || doc.depositAmount().signum() <= 0) {
             throw new ApiException(HttpStatus.CONFLICT, "ใบแจ้งรับมัดจำนี้มียอดมัดจำ 0 บาท จึงออกเอกสารไม่ได้");
         }
+        // The guard below is check-then-act: lock the deal row first so two drafts issued at once
+        // serialize, and the second one sees the first as ISSUED.
+        tickets.lockTicketForUpdate(doc.ticketId());
+        // Owner ruling 2026-10-23: one deposit notice per deal. A second draft (written before the
+        // first was issued) must not silently supersede the customer's document.
+        docs.findByTicket(doc.ticketId()).stream()
+            .filter(d -> d.id() != docId && "ISSUED".equals(d.status())).findFirst().ifPresent(d -> {
+                throw new ApiException(HttpStatus.CONFLICT,
+                    "ดีลนี้ออกใบแจ้งรับมัดจำเลขที่ " + d.docNumber() + " แล้ว จึงออกฉบับร่างนี้ไม่ได้");
+            });
         // Issuing advances the payment track — a paused/terminal deal must not move
         // (Phase 1 lifecycle gate; mirrors TicketService.requireActive).
         requireActiveLifecycle(s);
 
-        String docNumber = docs.issue(docId, actor.id(), actor.name())
+        String docNumber = docs.issue(docId, actor.id(), actor.name(), expectedUpdatedAt)
             .orElseThrow(() -> new ApiException(HttpStatus.CONFLICT,
                 "ใบแจ้งรับมัดจำนี้ถูกออกไปแล้วโดยผู้ใช้อื่น กรุณาโหลดข้อมูลใหม่แล้วลองอีกครั้ง"));
 
@@ -1120,7 +1160,7 @@ private DepositNoticeDto requireDraft(long docId) {
         DepositNoticeDto doc = docs.findById(docId)
             .orElseThrow(() -> new ApiException(HttpStatus.NOT_FOUND, "ไม่พบใบแจ้งรับมัดจำนี้"));
         if (!"DRAFT".equals(doc.status())) {
-            throw new ApiException(HttpStatus.CONFLICT, "ใบแจ้งรับมัดจำนี้ไม่ได้อยู่ในสถานะร่าง (DRAFT)");
+            throw new ApiException(HttpStatus.CONFLICT, DepositNoticeRepository.NOT_DRAFT);
         }
         return doc;
     }
@@ -1171,6 +1211,11 @@ private void requireRole(UserPrincipal actor, java.util.Set<String> allowed) {
         }
     }
 
+    /** 0.40 is a whole 40%; 0.405 and 0.3330 are not. */
+    private static boolean isWholePercent(BigDecimal fraction) {
+        return fraction.movePointRight(2).stripTrailingZeros().scale() <= 0;
+    }
+
     private String blankToNull(String value) {
         return value == null || value.isBlank() ? null : value;
     }
diff --git a/backend/src/test/java/th/co/glr/hr/dealquotation/DealQuotationConfirmOrderIntegrationTest.java b/backend/src/test/java/th/co/glr/hr/dealquotation/DealQuotationConfirmOrderIntegrationTest.java
index d615fff84..9a5c6e4a6 100644
--- a/backend/src/test/java/th/co/glr/hr/dealquotation/DealQuotationConfirmOrderIntegrationTest.java
+++ b/backend/src/test/java/th/co/glr/hr/dealquotation/DealQuotationConfirmOrderIntegrationTest.java
@@ -34,6 +34,8 @@
 import th.co.glr.hr.dealquotation.DealQuotationRequests.UpsertDealQuotationRequest;
 import th.co.glr.hr.deposit.DepositNoticeDraftRequest;
 import th.co.glr.hr.deposit.DepositNoticeDto;
+import th.co.glr.hr.deposit.DepositNoticeItemDto;
+import th.co.glr.hr.deposit.DepositNoticeItemRequest;
 import th.co.glr.hr.deposit.DepositNoticeRenderer;
 import th.co.glr.hr.deposit.DepositNoticeRepository;
 import th.co.glr.hr.deposit.DepositNoticeService;
@@ -252,7 +254,30 @@ void quotationFirstGhost_stillConfirms_landsAtOrderReceived_withQuotationLines_a
         DepositNoticeDto draft = depositNoticeService.createDraft(ghost,
             new DepositNoticeDraftRequest(null, null, null, null, null, null, null, null), salesActor);
         assertThat(draft.ticketId()).isEqualTo(ghost);
-        assertThat(draft.items()).isNotEmpty();
+        // Owner ruling 2026-10-23: the ส่วนลดพิเศษ ADJUSTMENT row (qty -1, -100.00) is folded into the
+        // goods lines by amount: TILE 10 x 100 and PLAIN 2 x 500 take 50.00 each. No negative qty, the
+        // descriptions are the goods lines' own, and the subtotal is the quotation's 1,900.
+        assertThat(draft.items())
+            .extracting(i -> i.qty().stripTrailingZeros().toPlainString(), i -> i.unitPrice().toPlainString(),
+                i -> i.netUnitPrice().toPlainString(), DepositNoticeItemDto::discountLabel)
+            .containsExactly(
+                org.assertj.core.groups.Tuple.tuple("10", "100.00", "95.00", "ส่วนลดพิเศษ 5 ต่อหน่วย"),
+                org.assertj.core.groups.Tuple.tuple("2", "500.00", "475.00", "ส่วนลดพิเศษ 25 ต่อหน่วย"));
+        assertThat(draft.items()).extracting(DepositNoticeItemDto::description).doesNotContain("ส่วนลดพิเศษ")
+            .last().isEqualTo("ค่าขนส่ง");
+        assertThat(draft.subtotal()).isEqualByComparingTo("1900.00");
+
+        // The page sends every line back on save; @PositiveOrZero qty used to refuse the whole PUT.
+        DepositNoticeDraftRequest pagePut = new DepositNoticeDraftRequest(
+            draft.customerName(), draft.customerTaxId(), draft.customerAddress(), draft.projectName(),
+            draft.reference(), draft.depositPercent(), draft.notes(),
+            draft.items().stream().map(i -> new DepositNoticeItemRequest(i.seq(), i.description(), i.qty(),
+                i.unit(), i.unitPrice(), i.discountLabel(), i.netUnitPrice())).toList(),
+            draft.updatedAt());
+        try (var factory = jakarta.validation.Validation.buildDefaultValidatorFactory()) {
+            assertThat(factory.getValidator().validate(pagePut)).isEmpty();
+        }
+        assertThat(depositNoticeService.update(draft.id(), pagePut, salesActor).subtotal()).isEqualByComparingTo("1900.00");
     }
 
     /** The same deposit-notice draft is REFUSED before confirmation — the negative half of "the money
diff --git a/backend/src/test/java/th/co/glr/hr/dealquotation/DealQuotationOutcomeIntegrationTest.java b/backend/src/test/java/th/co/glr/hr/dealquotation/DealQuotationOutcomeIntegrationTest.java
index 504680c7c..d406b1301 100644
--- a/backend/src/test/java/th/co/glr/hr/dealquotation/DealQuotationOutcomeIntegrationTest.java
+++ b/backend/src/test/java/th/co/glr/hr/dealquotation/DealQuotationOutcomeIntegrationTest.java
@@ -580,7 +580,7 @@ void issue_zeroAmountDraft_409_staysDraft_andConsumesNoNumber() {
         assertThatThrownBy(() -> depositNoticeService.issue(draft.id(), salesActor))
             .isInstanceOf(ApiException.class)
             .hasFieldOrPropertyWithValue("status", HttpStatus.CONFLICT)
-            .hasMessageContaining("0 บาท");
+            .hasMessageContaining("0%");
 
         Map<String, Object> row = jdbc.queryForMap(
             "SELECT status, doc_number FROM sales.deposit_notice WHERE deposit_notice_id = :id", Map.of("id", draft.id()));
diff --git a/backend/src/test/java/th/co/glr/hr/deposit/DepositNoticeAccountNotificationIntegrationTest.java b/backend/src/test/java/th/co/glr/hr/deposit/DepositNoticeAccountNotificationIntegrationTest.java
index 307817868..fa0d21a79 100644
--- a/backend/src/test/java/th/co/glr/hr/deposit/DepositNoticeAccountNotificationIntegrationTest.java
+++ b/backend/src/test/java/th/co/glr/hr/deposit/DepositNoticeAccountNotificationIntegrationTest.java
@@ -276,42 +276,6 @@ void issue_secondCallOnAnAlreadyIssuedDocIsRefused_andRaisesNoSecondAccountNotif
         assertThat(mailer.sent()).isEmpty();
     }
 
-    // ─────────────────────────────────────────────────────────────────────────────────────
-    // Revision re-issue (the DEPOSIT_NOTICE_ISSUED self-loop) notifies account again
-    // ─────────────────────────────────────────────────────────────────────────────────────
-
-    @Test
-    void issue_revisionReissue_notifiesAccountAgainMarkedAsARevision() {
-        DraftFixture fixture = buildDraftDepositNotice();
-        depositNoticeService.issue(fixture.docId(), salesActor);
-        assertThat(countAccountNotificationRows()).isEqualTo(1);
-        mailer.sent.clear();
-
-        // Repository-direct on purpose: DepositNoticeService.createDraft only ever sources the
-        // FIRST draft from the ticket's approved items/quotation, so building a literal SECOND
-        // draft (the revision) this way is the shortest path to the state under test here, and
-        // it is only issue() itself (called through the real service below) that this test cares
-        // about exercising faithfully.
-        long secondDocId = new DepositNoticeRepository(jdbc).createDraft(fixture.ticketId(),
-            new DepositNoticeDraftRequest("ACME Revision", "0100000000000", "Bangkok", "Showroom", "REF-REV",
-                new BigDecimal("0.50"), List.of(), null),
-            List.of(new DepositNoticeItemRequest(
-                1, "Revision item", new BigDecimal("1"), "แผ่น",
-                new BigDecimal("100.00"), null, new BigDecimal("100.00"))));
-
-        DepositNoticeDto revisionIssued = depositNoticeService.issue(secondDocId, salesActor);
-
-        assertThat(countAccountNotificationRows()).isEqualTo(2);
-        String secondMessage = (String) jdbc.queryForMap("""
-            SELECT message FROM hr.notification
-             WHERE employee_id = :accountId AND type = 'DEPOSIT_NOTICE_ISSUED'
-             ORDER BY notification_id DESC LIMIT 1
-            """, Map.of("accountId", accountEmployeeId)).get("message");
-        assertThat(secondMessage).contains("ฉบับแก้ไข");
-        assertThat(secondMessage).contains(revisionIssued.docNumber());
-        assertThat(mailer.recipients()).contains("account@glr.co.th");
-    }
-
     // ─────────────────────────────────────────────────────────────────────────────────────
     // Rollback: the critical AfterCommit trap this branch exists to avoid regressing
     // ─────────────────────────────────────────────────────────────────────────────────────
diff --git a/backend/src/test/java/th/co/glr/hr/deposit/DepositNoticeControllerTest.java b/backend/src/test/java/th/co/glr/hr/deposit/DepositNoticeControllerTest.java
index e71523e65..182d821bf 100644
--- a/backend/src/test/java/th/co/glr/hr/deposit/DepositNoticeControllerTest.java
+++ b/backend/src/test/java/th/co/glr/hr/deposit/DepositNoticeControllerTest.java
@@ -1,19 +1,27 @@
 package th.co.glr.hr.deposit;
 
+import static org.assertj.core.api.Assertions.assertThat;
 import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyLong;
 import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
 import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.put;
 import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.content;
 import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.header;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
 import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
 
 import java.math.BigDecimal;
+import java.time.Instant;
 import java.time.LocalDate;
 import java.util.List;
 import org.junit.jupiter.api.Test;
+import org.mockito.ArgumentCaptor;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.MediaType;
 import org.springframework.mock.web.MockHttpSession;
@@ -124,6 +132,42 @@ void createDraftRejectsInvalidDepositPercent() throws Exception {
             .andExpect(status().isBadRequest());
     }
 
+    @Test
+    void updateRejectsADepositPercentOutsideZeroTo100WithAThaiMessage() throws Exception {
+        for (String[] c : new String[][] {
+                {"1.5", "depositPercent เปอร์เซ็นต์มัดจำต้องไม่เกิน 100"},
+                {"-0.05", "depositPercent เปอร์เซ็นต์มัดจำต้องมากกว่า 0"},
+                {"0", "depositPercent เปอร์เซ็นต์มัดจำต้องมากกว่า 0"}}) {
+            mvc.perform(put("/api/deposit-notices/99")
+                    .session(session())
+                    .contentType(MediaType.APPLICATION_JSON)
+                    .content("{\"depositPercent\": " + c[0] + "}"))
+                .andExpect(status().isBadRequest())
+                .andExpect(jsonPath("$.message").value(c[1]));
+        }
+        verify(service, never()).update(anyLong(), any(), any());
+    }
+
+    // The record has a second, 8-argument constructor: the JSON must still bind through the
+    // canonical one, so the page's stamp reaches the service at full precision.
+    @Test
+    void updatePassesTheExpectedUpdatedAtStampThrough() throws Exception {
+        when(service.update(eq(99L), any(), any(UserPrincipal.class))).thenReturn(document());
+
+        mvc.perform(put("/api/deposit-notices/99")
+                .session(session())
+                .contentType(MediaType.APPLICATION_JSON)
+                .content("""
+                    {"depositPercent": 0.4, "expectedUpdatedAt": "2026-10-23T08:57:19.732123Z"}
+                    """))
+            .andExpect(status().isOk());
+
+        ArgumentCaptor<DepositNoticeDraftRequest> captor = ArgumentCaptor.forClass(DepositNoticeDraftRequest.class);
+        verify(service).update(eq(99L), captor.capture(), any(UserPrincipal.class));
+        assertThat(captor.getValue().expectedUpdatedAt().toInstant())
+            .isEqualTo(Instant.parse("2026-10-23T08:57:19.732123Z"));
+    }
+
     @Test
     void createDraftRejectsNegativeItemUnitPrice() throws Exception {
         String body = """
diff --git a/backend/src/test/java/th/co/glr/hr/deposit/DepositNoticeIssueGuardIntegrationTest.java b/backend/src/test/java/th/co/glr/hr/deposit/DepositNoticeIssueGuardIntegrationTest.java
index 42aaadd72..42d433225 100644
--- a/backend/src/test/java/th/co/glr/hr/deposit/DepositNoticeIssueGuardIntegrationTest.java
+++ b/backend/src/test/java/th/co/glr/hr/deposit/DepositNoticeIssueGuardIntegrationTest.java
@@ -11,6 +11,7 @@
 import com.fasterxml.jackson.databind.ObjectMapper;
 import java.math.BigDecimal;
 import java.time.LocalDate;
+import java.time.OffsetDateTime;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
@@ -209,27 +210,178 @@ void issue_repositoryLevelCallOnAlreadyIssuedRowRefusesWithoutRemintingDocNumber
         assertThat(reread.status()).isEqualTo("ISSUED");
     }
 
+    // The deal page's confirm dialog showed amounts read at T0; the draft was saved since. Issuing
+    // with the old stamp is refused (nothing numbered); with the current one it issues. Repository
+    // level: the service's one-per-deal guard would answer first on this fixture's ticket.
     @Test
-    void issue_secondDraftOnSameTicketSucceedsAndSupersedesTheFirst() {
-        // POSITIVE control: the guard must not block a genuine DRAFT -> ISSUED transition, and the
-        // pre-existing "supersede older ISSUED versions" behaviour in the same method must still
-        // work correctly with the new predicate in place.
+    void issue_withAStaleUpdatedAt_isRefused409_andNothingIsIssued() {
+        IssuedNoticeFixture fixture = buildTicketWithIssuedDepositNotice();
+        long draftId = depositNoticeRepository.createDraft(fixture.ticketId(), secondDraftHeader(), secondDraftItems());
+        OffsetDateTime loaded = depositNoticeRepository.findById(draftId).orElseThrow().updatedAt();
+        DepositNoticeDto saved = depositNoticeService.update(draftId, stampedRequest("0.40", secondDraftItems(), loaded), salesActor);
+
+        assertThatThrownBy(() -> depositNoticeRepository.issue(draftId, salesRepId, "x", loaded))
+            .isInstanceOfSatisfying(ApiException.class, e -> {
+                assertThat(e.getStatus()).isEqualTo(HttpStatus.CONFLICT);
+                assertThat(e.getMessage()).isEqualTo("ใบแจ้งรับมัดจำนี้ถูกแก้ไขโดยผู้ใช้อื่น กรุณาโหลดข้อมูลใหม่แล้วลองอีกครั้ง");
+            });
+        DepositNoticeDto reread = depositNoticeRepository.findById(draftId).orElseThrow();
+        assertThat(reread.status()).isEqualTo("DRAFT");
+        assertThat(reread.docNumber()).isNull();
+
+        assertThat(depositNoticeRepository.issue(draftId, salesRepId, "x", saved.updatedAt())).isPresent();
+    }
+
+    @Test
+    void issue_secondDraftOnSameTicket_refusedUntilBillable_thenStillRefusedWhileAnotherNoticeIsIssued() {
         IssuedNoticeFixture fixture = buildTicketWithIssuedDepositNotice();
 
+        // A stored percent outside whole 1-100 (a 0% ticket-route draft on a ไม่รับมัดจำ quotation,
+        // a pre-09-29 free-typed 0.3330, an out-of-range 1.5) or a 0-baht amount takes no number.
         long secondDocId = depositNoticeRepository.createDraft(
-            fixture.ticketId(), secondDraftHeader(), secondDraftItems());
-        Optional<String> secondDocNumber = depositNoticeRepository.issue(secondDocId, salesRepId, "Sales");
+            fixture.ticketId(), draftHeader(BigDecimal.ZERO), secondDraftItems());
+        assertIssueRefusedAndNothingChanged(fixture, secondDocId,
+            "ใบแจ้งรับมัดจำนี้มีเปอร์เซ็นต์มัดจำ 0% จึงออกเอกสารไม่ได้ (ต้องเป็นจำนวนเต็ม 1–100)");
+        assertIssueRefusedAndNothingChanged(fixture,
+            depositNoticeRepository.createDraft(fixture.ticketId(), draftHeader(new BigDecimal("0.3330")), secondDraftItems()),
+            "ใบแจ้งรับมัดจำนี้มีเปอร์เซ็นต์มัดจำ 33.3% จึงออกเอกสารไม่ได้ (ต้องเป็นจำนวนเต็ม 1–100)");
+        assertIssueRefusedAndNothingChanged(fixture,
+            depositNoticeRepository.createDraft(fixture.ticketId(), draftHeader(new BigDecimal("1.5")), secondDraftItems()),
+            "ใบแจ้งรับมัดจำนี้มีเปอร์เซ็นต์มัดจำ 150% จึงออกเอกสารไม่ได้ (ต้องเป็นจำนวนเต็ม 1–100)");
+        assertIssueRefusedAndNothingChanged(fixture,
+            depositNoticeRepository.createDraft(fixture.ticketId(), secondDraftHeader(), List.of(new DepositNoticeItemRequest(
+                1, "Free item", new BigDecimal("2"), "แผ่น", BigDecimal.ZERO, null, BigDecimal.ZERO))),
+            "ใบแจ้งรับมัดจำนี้มียอดมัดจำ 0 บาท จึงออกเอกสารไม่ได้");
+
+        // Owner ruling 2026-10-23: one deposit notice per deal. Even once the percent is billable,
+        // a SECOND draft cannot take a number while another notice is ISSUED (it used to silently
+        // supersede the customer's document): 409, the draft keeps no number, the first stays ISSUED.
+        depositNoticeService.update(secondDocId, secondDraftHeader(), salesActor);
+        assertIssueRefusedAndNothingChanged(fixture, secondDocId,
+            "ดีลนี้ออกใบแจ้งรับมัดจำเลขที่ " + fixture.docNumber() + " แล้ว จึงออกฉบับร่างนี้ไม่ได้");
+    }
+
+    // Owner ruling 2026-10-23: one deposit notice per deal. While one is ISSUED, neither create route
+    // drafts another (re-creating re-seeded the % from the quotation and a later issue silently
+    // superseded the customer's document). Re-versioning an issued notice is a separate change.
+    @Test
+    void createDraft_isRefusedOnBothRoutesWhileAnIssuedNoticeExists_noNewRow() {
+        IssuedNoticeFixture fixture = buildTicketWithIssuedDepositNotice();
+        String message = "ดีลนี้ออกใบแจ้งรับมัดจำเลขที่ " + fixture.docNumber() + " แล้ว จึงสร้างฉบับร่างใหม่ไม่ได้";
+
+        assertThatThrownBy(() -> depositNoticeService.createDraft(fixture.ticketId(),
+                new DepositNoticeDraftRequest(null, null, null, null, null, null, null, null), salesActor))
+            .isInstanceOfSatisfying(ApiException.class, e -> {
+                assertThat(e.getStatus()).isEqualTo(HttpStatus.CONFLICT);
+                assertThat(e.getMessage()).isEqualTo(message);
+            });
+        assertThatThrownBy(() -> orderConfirmation.createDepositNoticeFromQuotation(fixture.pricingRequestId(),
+                new CreateDepositNoticeFromQuotationRequest(null), salesActor))
+            .isInstanceOfSatisfying(ApiException.class, e -> {
+                assertThat(e.getStatus()).isEqualTo(HttpStatus.CONFLICT);
+                assertThat(e.getMessage()).isEqualTo(message);
+            });
+
+        assertThat(depositNoticeRepository.findByTicket(fixture.ticketId()))
+            .extracting(DepositNoticeDto::id).containsExactly(fixture.docId());
+    }
 
-        assertThat(secondDocNumber).isPresent();
-        assertThat(secondDocNumber.get()).isNotEqualTo(fixture.docNumber());
+    // Owner ruling 2026-10-23: sales may change the deposit % on a DRAFT; the amount follows.
+    @Test
+    void update_onADraft_changesThePercentAndTheAmountFollows() {
+        IssuedNoticeFixture fixture = buildTicketWithIssuedDepositNotice();
+        long draftId = depositNoticeRepository.createDraft(
+            fixture.ticketId(), secondDraftHeader(), secondDraftItems()); // 0.50 of 100.00
 
-        DepositNoticeDto firstReread = depositNoticeRepository.findById(fixture.docId()).orElseThrow();
-        assertThat(firstReread.status()).isEqualTo("SUPERSEDED");
-        assertThat(firstReread.docNumber()).isEqualTo(fixture.docNumber());
+        DepositNoticeDto updated = depositNoticeService.update(draftId, new DepositNoticeDraftRequest(
+            "ACME", "0100000000000", "Bangkok", "Showroom", "REF-2",
+            new BigDecimal("0.40"), List.of(), secondDraftItems()), salesActor);
+
+        // secondDraftItems: net x qty sums to 75.02 (unit x qty 90.00, stored amounts 75.03, nets alone 43.34).
+        assertThat(updated.depositPercent()).isEqualByComparingTo("0.40");
+        assertThat(updated.subtotal()).isEqualByComparingTo("75.02");
+        assertThat(updated.depositAmount()).isEqualByComparingTo("30.01");
+        assertThat(updated.vatAmount()).isEqualByComparingTo("2.10");
+        assertThat(updated.totalPayable()).isEqualByComparingTo("32.11");
+        assertThat(depositNoticeService.preview(draftId, salesActor))
+            .contains("ขอรับเงินมัดจำ (40%)")
+            .contains("30.01 บาท");
+
+        // A request without items (null, or an empty list) keeps the stored lines; the amount is
+        // recomputed from them at the new percent.
+        DepositNoticeDto nullItems = depositNoticeService.update(draftId, new DepositNoticeDraftRequest(
+            "ACME", "0100000000000", "Bangkok", "Showroom", "REF-2",
+            new BigDecimal("0.30"), List.of(), null), salesActor);
+        assertThat(nullItems.items()).isEqualTo(updated.items());
+        assertThat(nullItems.subtotal()).isEqualByComparingTo("75.02");
+        assertThat(nullItems.depositAmount()).isEqualByComparingTo("22.51");
 
-        DepositNoticeDto secondReread = depositNoticeRepository.findById(secondDocId).orElseThrow();
-        assertThat(secondReread.status()).isEqualTo("ISSUED");
-        assertThat(secondReread.docNumber()).isEqualTo(secondDocNumber.get());
+        DepositNoticeDto emptyItems = depositNoticeService.update(draftId, new DepositNoticeDraftRequest(
+            "ACME", "0100000000000", "Bangkok", "Showroom", "REF-2",
+            new BigDecimal("0.20"), List.of(), List.of()), salesActor);
+        assertThat(emptyItems.items()).isEqualTo(updated.items());
+        assertThat(emptyItems.subtotal()).isEqualByComparingTo("75.02");
+        assertThat(emptyItems.depositAmount()).isEqualByComparingTo("15.00");
+    }
+
+    // Two tabs on one draft: both loaded the same updatedAt. A saves; B's save with that now-stale
+    // stamp is refused and changes nothing; reloading (the fresh stamp) saves.
+    @Test
+    void update_withAStaleUpdatedAt_isRefused409_andTheFirstSaveStands() {
+        IssuedNoticeFixture fixture = buildTicketWithIssuedDepositNotice();
+        long draftId = depositNoticeRepository.createDraft(fixture.ticketId(), secondDraftHeader(), secondDraftItems());
+        OffsetDateTime loaded = depositNoticeRepository.findById(draftId).orElseThrow().updatedAt();
+
+        DepositNoticeDto savedByA = depositNoticeService.update(draftId, stampedRequest("0.40", secondDraftItems(), loaded), salesActor);
+
+        List<DepositNoticeItemRequest> tabBItems = List.of(new DepositNoticeItemRequest(
+            1, "Tab B item", new BigDecimal("1"), "แผ่น", new BigDecimal("999.00"), null, new BigDecimal("999.00")));
+        assertThatThrownBy(() -> depositNoticeService.update(draftId, stampedRequest("0.30", tabBItems, loaded), salesActor))
+            .isInstanceOfSatisfying(ApiException.class, e -> {
+                assertThat(e.getStatus()).isEqualTo(HttpStatus.CONFLICT);
+                assertThat(e.getMessage()).isEqualTo("ใบแจ้งรับมัดจำนี้ถูกแก้ไขโดยผู้ใช้อื่น กรุณาโหลดข้อมูลใหม่แล้วลองอีกครั้ง");
+            });
+        DepositNoticeDto reread = depositNoticeRepository.findById(draftId).orElseThrow();
+        assertThat(reread.depositPercent()).isEqualByComparingTo("0.40");
+        assertThat(reread.depositAmount()).isEqualByComparingTo(savedByA.depositAmount());
+        assertThat(reread.items()).isEqualTo(savedByA.items());
+        assertThat(reread.updatedAt()).isEqualTo(savedByA.updatedAt());
+
+        DepositNoticeDto reloaded = depositNoticeService.update(
+            draftId, stampedRequest("0.30", tabBItems, savedByA.updatedAt()), salesActor);
+        assertThat(reloaded.depositPercent()).isEqualByComparingTo("0.30");
+        assertThat(reloaded.subtotal()).isEqualByComparingTo("999.00");
+    }
+
+    @Test
+    void update_onAnIssuedNotice_refusesThePercentEditWith409_rowUnchanged() {
+        IssuedNoticeFixture fixture = buildTicketWithIssuedDepositNotice();
+        DepositNoticeDto before = depositNoticeRepository.findById(fixture.docId()).orElseThrow();
+
+        assertThatThrownBy(() -> depositNoticeService.update(fixture.docId(), new DepositNoticeDraftRequest(
+                "ACME", "0100000000000", "Bangkok", "Showroom", "REF-2",
+                new BigDecimal("0.40"), List.of(), secondDraftItems()), salesActor))
+            .isInstanceOfSatisfying(ApiException.class, e -> {
+                assertThat(e.getStatus()).isEqualTo(HttpStatus.CONFLICT);
+                assertThat(e.getMessage()).isEqualTo("ใบแจ้งรับมัดจำนี้ไม่ได้อยู่ในสถานะร่าง (DRAFT)");
+            });
+
+        // Repository level: a save that passed requireDraft before issue() committed reaches the
+        // UPDATE with the row already ISSUED. It must refuse before touching the lines, which the
+        // PDF/XLSX print.
+        assertThatThrownBy(() -> depositNoticeRepository.update(fixture.docId(), new DepositNoticeDraftRequest(
+                "ACME", "0100000000000", "Bangkok", "Showroom", "REF-2",
+                new BigDecimal("0.40"), List.of(), secondDraftItems()), before.items()))
+            .isInstanceOfSatisfying(ApiException.class, e -> {
+                assertThat(e.getStatus()).isEqualTo(HttpStatus.CONFLICT);
+                assertThat(e.getMessage()).isEqualTo("ใบแจ้งรับมัดจำนี้ไม่ได้อยู่ในสถานะร่าง (DRAFT)");
+            });
+
+        DepositNoticeDto reread = depositNoticeRepository.findById(fixture.docId()).orElseThrow();
+        assertThat(reread.status()).isEqualTo("ISSUED");
+        assertThat(reread.depositPercent()).isEqualByComparingTo(before.depositPercent());
+        assertThat(reread.depositAmount()).isEqualByComparingTo(before.depositAmount());
+        assertThat(reread.items()).isEqualTo(before.items());
     }
 
     // ─────────────────────────────────────────────────────────────────────────────────────
@@ -240,15 +392,43 @@ void issue_secondDraftOnSameTicketSucceedsAndSupersedesTheFirst() {
     private record IssuedNoticeFixture(long ticketId, long pricingRequestId, long docId, String docNumber) {}
 
     private DepositNoticeDraftRequest secondDraftHeader() {
+        return draftHeader(new BigDecimal("0.50"));
+    }
+
+    private DepositNoticeDraftRequest draftHeader(BigDecimal depositPercent) {
         return new DepositNoticeDraftRequest(
             "ACME", "0100000000000", "Bangkok", "Showroom", "REF-2",
-            new BigDecimal("0.50"), List.of(), null);
+            depositPercent, List.of(), null);
     }
 
+    private DepositNoticeDraftRequest stampedRequest(String depositPercent, List<DepositNoticeItemRequest> items,
+                                                     OffsetDateTime expectedUpdatedAt) {
+        return new DepositNoticeDraftRequest("ACME", "0100000000000", "Bangkok", "Showroom", "REF-2",
+            new BigDecimal(depositPercent), List.of(), items, expectedUpdatedAt);
+    }
+
+    // Fractional qty, net below unit: net x qty (49.995 + 25.025 = 75.02), unit x qty (90.00), the
+    // per-line rounded amounts (50.00 + 25.03 = 75.03) and the nets alone (43.34) all differ.
     private List<DepositNoticeItemRequest> secondDraftItems() {
-        return List.of(new DepositNoticeItemRequest(
-            1, "Second draft item", new BigDecimal("1"), "แผ่น",
-            new BigDecimal("100.00"), null, new BigDecimal("100.00")));
+        return List.of(
+            new DepositNoticeItemRequest(1, "Second draft item A", new BigDecimal("1.5"), "แผ่น",
+                new BigDecimal("40.00"), "ส่วนลด 6.67 ต่อหน่วย", new BigDecimal("33.33")),
+            new DepositNoticeItemRequest(2, "Second draft item B", new BigDecimal("2.5"), "แผ่น",
+                new BigDecimal("12.00"), "ส่วนลด 1.99 ต่อหน่วย", new BigDecimal("10.01")));
+    }
+
+    private void assertIssueRefusedAndNothingChanged(IssuedNoticeFixture fixture, long draftId, String message) {
+        assertThatThrownBy(() -> depositNoticeService.issue(draftId, salesActor))
+            .isInstanceOfSatisfying(ApiException.class, e -> {
+                assertThat(e.getStatus()).isEqualTo(HttpStatus.CONFLICT);
+                assertThat(e.getMessage()).isEqualTo(message);
+            });
+        DepositNoticeDto draft = depositNoticeRepository.findById(draftId).orElseThrow();
+        assertThat(draft.status()).isEqualTo("DRAFT");
+        assertThat(draft.docNumber()).isNull();
+        DepositNoticeDto first = depositNoticeRepository.findById(fixture.docId()).orElseThrow();
+        assertThat(first.status()).isEqualTo("ISSUED");
+        assertThat(first.docNumber()).isEqualTo(fixture.docNumber());
     }
 
     private IssuedNoticeFixture buildTicketWithIssuedDepositNotice() {
diff --git a/backend/src/test/java/th/co/glr/hr/deposit/DepositNoticeServiceTest.java b/backend/src/test/java/th/co/glr/hr/deposit/DepositNoticeServiceTest.java
index 0472cc0bd..5358e59c0 100644
--- a/backend/src/test/java/th/co/glr/hr/deposit/DepositNoticeServiceTest.java
+++ b/backend/src/test/java/th/co/glr/hr/deposit/DepositNoticeServiceTest.java
@@ -9,12 +9,14 @@
 import static org.mockito.ArgumentMatchers.isNull;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 import java.math.BigDecimal;
 import java.time.Instant;
 import java.time.LocalDate;
+import java.time.OffsetDateTime;
 import java.util.List;
 import java.util.Optional;
 import org.junit.jupiter.api.Test;
@@ -61,8 +63,8 @@ class DepositNoticeServiceTest {
 
     private final UserPrincipal owner = new UserPrincipal(
         1L, "sales@glr.co.th", "Sales", "sales", 1L, true, LocalDate.of(2026, 1, 1), false, 1L, false);
-    // sales_manager: read-only oversight of deposit notices — never owns a ticket
-    // (no create access), so every owner-gated write is denied by ownership alone.
+    // sales_manager: read-only oversight of deposit notices. It can create (and so own) a deal
+    // since deal entry was widened, so every deposit-notice write is role-gated to sales.
     private final UserPrincipal salesManagerActor = new UserPrincipal(
         8L, "sales_manager@glr.co.th", "Sales Manager", "sales_manager", 8L, true,
         LocalDate.of(2026, 1, 1), false, null, false);
@@ -73,7 +75,7 @@ class DepositNoticeServiceTest {
     void issue_advancesPaymentTrackAndKeepsTicketStatus() {
         stubDraft(99L, 10L);
         stubTicket(10L, TicketStatus.QUOTATION_ISSUED, "CUSTOMER_CONFIRMED");
-        when(docs.issue(99L, 1L, "Sales")).thenReturn(Optional.of("GLRD69001"));
+        when(docs.issue(eq(99L), eq(1L), eq("Sales"), any())).thenReturn(Optional.of("GLRD69001"));
 
         service.issue(99L, owner);
 
@@ -88,6 +90,24 @@ void issue_advancesPaymentTrackAndKeepsTicketStatus() {
             eq(TicketEventKind.DOCUMENT_ISSUED), anyString(), anyString(), anyString());
     }
 
+    // One notice per deal: the "another notice is ISSUED" guard is check-then-act, so the ticket
+    // row is locked first — two drafts issued at once serialize and the second sees the first.
+    // (A real two-thread race is not reproducible in this suite; this pins the order.)
+    @Test
+    void issue_locksTheTicketRowBeforeReadingTheOneIssuedGuard_andPassesTheStampOn() {
+        stubDraft(99L, 10L);
+        stubTicket(10L, TicketStatus.QUOTATION_ISSUED, "CUSTOMER_CONFIRMED");
+        OffsetDateTime stamp = OffsetDateTime.parse("2026-10-23T08:57:19.732123Z");
+        when(docs.issue(eq(99L), eq(1L), eq("Sales"), eq(stamp))).thenReturn(Optional.of("GLRD69001"));
+
+        service.issue(99L, stamp, owner);
+
+        var order = org.mockito.Mockito.inOrder(ticketRepo, docs);
+        order.verify(ticketRepo).lockTicketForUpdate(10L);
+        order.verify(docs).findByTicket(10L);
+        order.verify(docs).issue(99L, 1L, "Sales", stamp);
+    }
+
     @Test
     void issue_requiresQuotationIssuedStatus() {
         stubDraft(99L, 10L);
@@ -120,7 +140,7 @@ void issue_requiresCustomerConfirmedOrDepositNoticeIssuedPayment() {
     void issue_fromDepositNoticeIssued_isNowAllowedAsARevision() {
         stubDraft(99L, 10L);
         stubTicket(10L, TicketStatus.QUOTATION_ISSUED, "DEPOSIT_NOTICE_ISSUED");
-        when(docs.issue(99L, 1L, "Sales")).thenReturn(Optional.of("GLRD69002"));
+        when(docs.issue(eq(99L), eq(1L), eq("Sales"), any())).thenReturn(Optional.of("GLRD69002"));
 
         service.issue(99L, owner); // must not throw
 
@@ -808,14 +828,18 @@ void createDraft_rejectsSalesManagerRole() {
 
     @Test
     void update_rejectsSalesManagerRole() {
-        // update() has NO role gate — only requireTicketOwner. sales_manager can
-        // never own a ticket, so the ownership check alone denies it.
+        // Role-gated (SALES_ROLES) like createDraft and issue: a sales_manager that OWNS the deal
+        // (stubTicket's createdById is 1) passes the owner check, so only the role gate refuses it.
+        UserPrincipal salesManagerOwner = new UserPrincipal(
+            1L, "sales_manager@glr.co.th", "Sales Manager", "sales_manager", 1L, true,
+            LocalDate.of(2026, 1, 1), false, null, false);
         stubDraft(99L, 10L);
         stubTicket(10L, TicketStatus.APPROVED, null);
 
         assertForbidden(() -> service.update(99L,
             new DepositNoticeDraftRequest(null, null, null, null, null, null, null, null),
-            salesManagerActor));
+            salesManagerOwner));
+        verify(docs, never()).update(anyLong(), any(), any());
     }
 
     @Test
@@ -934,7 +958,8 @@ void createDraft_legacyApprovedPriceItemsWinOverQuotationChainWhenBothExist() {
     // 2026-10-23) ────
     // The governing quotation's percent (DepositNoticeRepository#findGoverningQuotation: legacy
     // 50, new-engine its own, blank 30); a caller-supplied percent is never read on create, and
-    // 0.50 applies only when the ticket has no live quotation.
+    // 0.50 applies only when the ticket has no live quotation. update() then lets sales change it
+    // on a DRAFT; an ISSUED notice refuses any edit (requireDraft, 409).
 
     @Test
     void createDraft_sourcesDepositPercentFromQuotation_ignoringCallerSuppliedValue() {
@@ -1003,25 +1028,101 @@ void createDraft_takesLinesPercentAndReferenceFromTheGoverningNewEngineQuotation
     }
 
     @Test
-    void update_preservesTheDraftsOwnStoredDepositPercent_ignoringCallerSuppliedValue() {
+    void update_onADraft_persistsTheCallersDepositPercent() {
         // stubDraft's fixture stores depositPercent = 0.50 on doc 99 / ticket 10.
         stubDraft(99L, 10L);
         stubTicket(10L, TicketStatus.APPROVED, null);
 
-        // A caller sends 0.99 — must never reach the repository update.
         service.update(99L,
             new DepositNoticeDraftRequest("ACME", null, null, null, "REF-2",
-                new BigDecimal("0.99"), null, null),
+                new BigDecimal("0.40"), null, null),
             owner);
 
         ArgumentCaptor<DepositNoticeDraftRequest> captor = ArgumentCaptor.forClass(DepositNoticeDraftRequest.class);
-        verify(docs).update(eq(99L), captor.capture());
-        assertThat(captor.getValue().depositPercent()).isEqualByComparingTo("0.50");
-        // Every other field still passes through untouched — only depositPercent is overridden.
+        verify(docs).update(eq(99L), captor.capture(), any());
+        assertThat(captor.getValue().depositPercent()).isEqualByComparingTo("0.40");
         assertThat(captor.getValue().customerName()).isEqualTo("ACME");
         assertThat(captor.getValue().reference()).isEqualTo("REF-2");
     }
 
+    @Test
+    void update_withNoDepositPercent_keepsTheDraftsStoredPercent() {
+        stubDraft(99L, 10L); // stored 0.50
+        stubTicket(10L, TicketStatus.APPROVED, null);
+
+        service.update(99L,
+            new DepositNoticeDraftRequest("ACME", null, null, null, "REF-2", null, null, null),
+            owner);
+
+        ArgumentCaptor<DepositNoticeDraftRequest> captor = ArgumentCaptor.forClass(DepositNoticeDraftRequest.class);
+        verify(docs).update(eq(99L), captor.capture(), any());
+        assertThat(captor.getValue().depositPercent()).isEqualByComparingTo("0.50");
+    }
+
+    @Test
+    void update_refusesZeroAndANewFractionalPercent_butAStoredFractionSentBackUnchangedSaves() {
+        // Stored 0.3330: free input from before the whole-percent rule. The page shows it as 33.
+        stubDraft(99L, 10L, new BigDecimal("0.3330"));
+        stubTicket(10L, TicketStatus.APPROVED, null);
+
+        assertThatThrownBy(() -> service.update(99L,
+                new DepositNoticeDraftRequest("ACME", null, null, null, "REF-2", BigDecimal.ZERO, null, null),
+                owner))
+            .isInstanceOfSatisfying(ApiException.class, e -> {
+                assertThat(e.getStatus()).isEqualTo(HttpStatus.BAD_REQUEST);
+                assertThat(e.getMessage()).isEqualTo("เปอร์เซ็นต์มัดจำต้องมากกว่า 0");
+            });
+        // 40.5% would print as "41%" on the document while billing 40.5%.
+        assertThatThrownBy(() -> service.update(99L,
+                new DepositNoticeDraftRequest("ACME", null, null, null, "REF-2", new BigDecimal("0.405"), null, null),
+                owner))
+            .isInstanceOfSatisfying(ApiException.class, e -> {
+                assertThat(e.getStatus()).isEqualTo(HttpStatus.BAD_REQUEST);
+                assertThat(e.getMessage()).isEqualTo("เปอร์เซ็นต์มัดจำต้องเป็นจำนวนเต็ม");
+            });
+        verify(docs, never()).update(anyLong(), any(), any());
+
+        // The stored value sent back unchanged (0.333 == 0.3330) still saves the rest of the draft;
+        // a whole percent replaces it.
+        service.update(99L,
+            new DepositNoticeDraftRequest("ACME", null, null, null, "REF-2", new BigDecimal("0.333"), null, null),
+            owner);
+        service.update(99L,
+            new DepositNoticeDraftRequest("ACME", null, null, null, "REF-2", new BigDecimal("0.40"), null, null),
+            owner);
+        ArgumentCaptor<DepositNoticeDraftRequest> captor = ArgumentCaptor.forClass(DepositNoticeDraftRequest.class);
+        verify(docs, times(2)).update(eq(99L), captor.capture(), any());
+        assertThat(captor.getAllValues())
+            .extracting(r -> r.depositPercent().stripTrailingZeros().toPlainString())
+            .containsExactly("0.333", "0.4");
+    }
+
+    // DepositNoticeRepository#foldAdjustments (owner rulings 2026-10-23, "2 decimals for all"): the
+    // ส่วนลดพิเศษ amount is spread by line amount, each share HALF_UP to 2 dp, each new net price
+    // 2 dp. There is no remainder trick: the notice total is the sum of its own 2 dp lines (here
+    // 200.01, a cent over the quotation's 200.00). A line keeps the quotation's own discount wording
+    // and gains the folded discount after it; a line the fold did not touch keeps its label as is.
+    @Test
+    void foldAdjustments_keepsEachLinesOwnLabel_appendsTheFoldedDiscount_andTotalsFollowTheTwoDpLines() {
+        List<DepositNoticeItemRequest> folded = DepositNoticeRepository.foldAdjustments(List.of(
+            foldLine(1, "1", "100.00", "ส่วนลด 5 ต่อหน่วย"), foldLine(2, "1", "100.00", null),
+            foldLine(3, "1", "100.00", null), foldLine(4, "2", "0.00", "ส่วนลด 9 ต่อหน่วย")),
+            new BigDecimal("-100.00"));
+
+        assertThat(folded).extracting(it -> it.netUnitPrice().toPlainString())
+            .containsExactly("66.67", "66.67", "66.67", "0.00");
+        assertThat(folded.stream().map(it -> it.netUnitPrice().multiply(it.qty())).reduce(BigDecimal.ZERO, BigDecimal::add))
+            .isEqualByComparingTo("200.01");
+        assertThat(folded).extracting(DepositNoticeItemRequest::discountLabel).containsExactly(
+            "ส่วนลด 5 ต่อหน่วย + ส่วนลดพิเศษ 33.33 ต่อหน่วย", "ส่วนลดพิเศษ 33.33 ต่อหน่วย",
+            "ส่วนลดพิเศษ 33.33 ต่อหน่วย", "ส่วนลด 9 ต่อหน่วย");
+    }
+
+    private static DepositNoticeItemRequest foldLine(int seq, String qty, String net, String label) {
+        return new DepositNoticeItemRequest(seq, "Line " + seq, new BigDecimal(qty), "แผ่น",
+            new BigDecimal(net), label, new BigDecimal(net));
+    }
+
     private static void assertForbidden(org.assertj.core.api.ThrowableAssert.ThrowingCallable action) {
         assertThatThrownBy(action)
             .isInstanceOfSatisfying(ApiException.class, e ->
@@ -1031,10 +1132,14 @@ private static void assertForbidden(org.assertj.core.api.ThrowableAssert.Throwin
     // ── fixtures ─────────────────────────────────────────────────────────────
 
     private void stubDraft(long docId, long ticketId) {
+        stubDraft(docId, ticketId, new BigDecimal("0.50"));
+    }
+
+    private void stubDraft(long docId, long ticketId, BigDecimal depositPercent) {
         DepositNoticeDto draft = new DepositNoticeDto(
             docId, ticketId, "DEPOSIT_NOTICE", 1, null, null, "DRAFT",
             "ACME", "0100000000000", "Bangkok", "Showroom", "REF-1", "THB",
-            new BigDecimal("0.50"), new BigDecimal("1000.00"), new BigDecimal("500.00"),
+            depositPercent, new BigDecimal("1000.00"), new BigDecimal("500.00"),
             new BigDecimal("0.07"), new BigDecimal("35.00"), new BigDecimal("535.00"),
             List.of(), false, false, "Sales", "Preparer", null, null, List.of());
         when(docs.findById(docId)).thenReturn(Optional.of(draft));
diff --git a/backend/src/test/java/th/co/glr/hr/deposit/RemainingInvoiceServiceIntegrationTest.java b/backend/src/test/java/th/co/glr/hr/deposit/RemainingInvoiceServiceIntegrationTest.java
index 2c7338774..8abc6a411 100644
--- a/backend/src/test/java/th/co/glr/hr/deposit/RemainingInvoiceServiceIntegrationTest.java
+++ b/backend/src/test/java/th/co/glr/hr/deposit/RemainingInvoiceServiceIntegrationTest.java
@@ -811,11 +811,11 @@ null, new BigDecimal("10"), new BigDecimal("0.36"), WastageCalculator.QUANTITY_M
 
     /** A SECOND, wholly separate pricing-request chain on an ALREADY-EXISTING ticket — its own
      * catalog product, pricing request, factory quote, pricing decision and CustomerQuotation,
-     * driven to ACCEPTED + its own issued deposit notice, exactly like {@link #buildAcceptedDeal}
+     * driven to ACCEPTED (no second deposit notice: one ISSUED per deal), exactly like {@link #buildAcceptedDeal}
      * except it reuses the given ticket (and its first ticket item) instead of creating a new one.
      * Used by the O2 (one live remaining invoice per deal) tests to prove superseding/blocking
      * reaches a genuinely different chain, not merely a different id on the same fixture. */
-    private DealFixture buildSecondAcceptedQuotationChain(long ticketId, UserPrincipal owner, String label) {
+    private void buildSecondAcceptedQuotationChain(long ticketId, UserPrincipal owner, String label) {
         long catalogProductId = insertCatalogProduct(FACTORY, "IT",
             "TEST-RI-" + label + "-" + UUID.randomUUID().toString().substring(0, 8),
             new BigDecimal("100.00"), "THB", "per_piece");
@@ -866,11 +866,14 @@ null, new BigDecimal("10"), new BigDecimal("0.36"), WastageCalculator.QUANTITY_M
 
         orderConfirmation.confirmOrder(pricingRequestId,
             new ConfirmOrderRequest(UUID.randomUUID().toString()), owner);
-        DepositNoticeDto depositDraft = orderConfirmation.createDepositNoticeFromQuotation(pricingRequestId,
-            new CreateDepositNoticeFromQuotationRequest(null), owner);
-        DepositNoticeDto depositIssued = depositNoticeService.issue(depositDraft.id(), owner);
+        // Chain B has no deposit notice of its own, so it qualifies for a remaining invoice only through
+        // the bypass branch: flip the deal to NOT_REQUIRED (chain A's drafts/invoices were made earlier).
+        jdbc.update("UPDATE sales.ticket SET deposit_policy = 'NOT_REQUIRED' WHERE ticket_id = :id",
+            Map.of("id", ticketId));
+        // No deposit notice for chain B: a deal has at most one ISSUED deposit notice (owner ruling
+        // 2026-10-28), so chain A's stays the deal's only one; the remaining-invoice rules under test
+        // key off the accepted quotations, not a second notice.
 
-        return new DealFixture(ticketId, pricingRequestId, depositIssued.id());
     }
 
     private void driveDraftPricingRequestToQuotationAccepted(long pricingRequestId, BigDecimal quantity, UserPrincipal owner) {
diff --git a/backend/src/test/java/th/co/glr/hr/ticket/PaymentTrackIntegrationTest.java b/backend/src/test/java/th/co/glr/hr/ticket/PaymentTrackIntegrationTest.java
index f6301a785..61a005e91 100644
--- a/backend/src/test/java/th/co/glr/hr/ticket/PaymentTrackIntegrationTest.java
+++ b/backend/src/test/java/th/co/glr/hr/ticket/PaymentTrackIntegrationTest.java
@@ -272,7 +272,7 @@ void bypassPath_walksEndToEnd_nullThroughFullyPaid_neverVisitsDepositNoticeIssue
     }
 
     @Test
-    void depositNoticeRevision_secondIssueSucceeds_mintsNewDocSupersedesFirst_paymentStatusStaysDepositNoticeIssued() {
+    void depositNoticeSecondIssue_isRefused_firstStaysIssued_noNumberConsumed_paymentStatusUnchanged() {
         Deal deal = buildDealToQuotationAccepted("revision");
         orderConfirmation.confirmOrder(
             deal.pricingRequestId(), new ConfirmOrderRequest(UUID.randomUUID().toString()), salesActor);
@@ -281,18 +281,26 @@ void depositNoticeRevision_secondIssueSucceeds_mintsNewDocSupersedesFirst_paymen
         DepositNoticeDto firstIssued = depositNoticeService.issue(firstDraft.id(), salesActor);
         assertThat(paymentStatusOf(deal.ticketId())).isEqualTo(PaymentTrack.DEPOSIT_NOTICE_ISSUED);
 
-        // A revision: a NEW draft on the SAME ticket, issued while payment_status is still
-        // DEPOSIT_NOTICE_ISSUED — PaymentTrack's one legal self-loop (guard e).
-        long secondDraftId = depositNoticeService.createDraft(deal.ticketId(), bareDraftRequest(), salesActor).id();
-        DepositNoticeDto secondIssued = depositNoticeService.issue(secondDraftId, salesActor);
-
-        assertThat(secondIssued.docNumber()).isNotEqualTo(firstIssued.docNumber());
-        assertThat(secondIssued.status()).isEqualTo("ISSUED");
-        // PR #698's "AND status = 'DRAFT'" guard on DepositNoticeRepository.issue composes with
-        // this change: the second row really was DRAFT (createDraft never touches payment_status)
-        // when it was issued.
+        // Owner ruling 2026-10-23: one deposit notice per deal. The create routes refuse a draft
+        // while a notice is ISSUED; a second draft that exists anyway (written by the repository,
+        // as a concurrent or pre-ruling draft would be) is refused at issue(), so the
+        // DEPOSIT_NOTICE_ISSUED self-loop is not reachable through this service.
+        assertThatThrownBy(() -> depositNoticeService.createDraft(deal.ticketId(), bareDraftRequest(), salesActor))
+            .isInstanceOfSatisfying(ApiException.class,
+                e -> assertThat(e.getStatus()).isEqualTo(HttpStatus.CONFLICT));
+        long secondDraftId = depositNoticeRepository.createDraft(
+            deal.ticketId(), bareDraftRequest(), bareDraftRequest().items());
+        assertThatThrownBy(() -> depositNoticeService.issue(secondDraftId, salesActor))
+            .isInstanceOfSatisfying(ApiException.class, e -> {
+                assertThat(e.getStatus()).isEqualTo(HttpStatus.CONFLICT);
+                assertThat(e.getMessage()).contains(firstIssued.docNumber());
+            });
+
+        DepositNoticeDto second = depositNoticeRepository.findById(secondDraftId).orElseThrow();
+        assertThat(second.status()).isEqualTo("DRAFT");
+        assertThat(second.docNumber()).isNull();
         DepositNoticeDto firstReread = depositNoticeRepository.findById(firstIssued.id()).orElseThrow();
-        assertThat(firstReread.status()).isEqualTo("SUPERSEDED");
+        assertThat(firstReread.status()).isEqualTo("ISSUED");
         assertThat(firstReread.docNumber()).isEqualTo(firstIssued.docNumber());
         assertThat(paymentStatusOf(deal.ticketId())).isEqualTo(PaymentTrack.DEPOSIT_NOTICE_ISSUED);
     }
diff --git a/frontend/src/api/hrApi.js b/frontend/src/api/hrApi.js
index 5382e61cd..88e500b14 100644
--- a/frontend/src/api/hrApi.js
+++ b/frontend/src/api/hrApi.js
@@ -480,7 +480,8 @@ export const api = {
     get: (id) => apiRequest(API_ROUTES.depositNotices.get(id)),
     update: (id, payload) => apiRequest(API_ROUTES.depositNotices.update(id), { method: 'PUT', body: payload }),
     preview: (id) => apiRequest(API_ROUTES.depositNotices.preview(id), { method: 'POST' }),
-    issue: (id) => apiRequest(API_ROUTES.depositNotices.issue(id), { method: 'POST' }),
+    // payload.expectedUpdatedAt (optional): the draft's updatedAt as the caller last read it; 409 if it moved on.
+    issue: (id, payload) => apiRequest(API_ROUTES.depositNotices.issue(id), { method: 'POST', body: payload }),
     downloadXlsx: async (id) => {
       const res = await fetch(API_ROUTES.depositNotices.file(id, 'xlsx'), { credentials: 'include' });
       if (!res.ok) throw new Error('Download failed');
diff --git a/frontend/src/api/mockApi.depositNotices.test.js b/frontend/src/api/mockApi.depositNotices.test.js
index f54b3ad77..cd731ff92 100644
--- a/frontend/src/api/mockApi.depositNotices.test.js
+++ b/frontend/src/api/mockApi.depositNotices.test.js
@@ -425,6 +425,119 @@ describe('mockApi.depositNotices.issue hasPdf/hasXlsx (issue #752: mock reproduc
   });
 });
 
+// Owner ruling 2026-10-23 (mirrors DepositNoticeService.update): sales may change the deposit %
+// on a DRAFT and the amount follows; 0 is refused; an ISSUED notice refuses every edit.
+describe('mockApi.depositNotices.update deposit percent', () => {
+  it('on a DRAFT takes the new percent and recomputes the amount; 0, over 100% and fractional are refused', async () => {
+    const { ticketId } = await driveTicketToAcceptedQuotation();
+    const { depositNotice: draft } = await api.depositNotices.createDraft(ticketId, { notes: [] });
+    expect(draft.subtotal).toBeGreaterThan(0);
+
+    // Items sent the way DepositNoticePage sends them on save.
+    const { depositNotice: updated } = await api.depositNotices.update(draft.id, { depositPercent: 0.4, items: draft.items });
+    expect(updated.depositPercent).toBe(0.4);
+    expect(updated.depositAmount).toBe(Math.round(draft.subtotal * 0.4 * 100) / 100);
+
+    // DepositNoticeDraftRequest's @DecimalMin/@DecimalMax run before the service (field-prefixed).
+    await expect(api.depositNotices.update(draft.id, { depositPercent: 0 }))
+      .rejects.toMatchObject({ status: 400, message: 'depositPercent เปอร์เซ็นต์มัดจำต้องมากกว่า 0' });
+    await expect(api.depositNotices.update(draft.id, { depositPercent: 1.5 }))
+      .rejects.toMatchObject({ status: 400, message: 'depositPercent เปอร์เซ็นต์มัดจำต้องไม่เกิน 100' });
+    await expect(api.depositNotices.update(draft.id, { depositPercent: 0.405 }))
+      .rejects.toMatchObject({ status: 400, message: 'เปอร์เซ็นต์มัดจำต้องเป็นจำนวนเต็ม' });
+    const { depositNotice: afterRejects } = await api.depositNotices.get(draft.id);
+    expect(afterRejects.depositPercent).toBe(0.4);
+    expect(afterRejects.depositAmount).toBe(updated.depositAmount);
+    // 0.29 * 100 is 28.999999999999996 in floating point; it is still a whole 29%.
+    await api.depositNotices.update(draft.id, { depositPercent: 0.29, items: draft.items });
+    const { depositNotice: reread } = await api.depositNotices.get(draft.id);
+    expect(reread.depositPercent).toBe(0.29);
+  });
+
+  // @Valid runs before DepositNoticeService.update looks anything up, so a bad % is a 400 even
+  // for a notice that does not exist or is already issued.
+  it('validates the % before the 404 and 409 lookups', async () => {
+    await api.auth.login({ role: 'sales' });
+    await expect(api.depositNotices.update(999999, { depositPercent: 1.5 }))
+      .rejects.toMatchObject({ status: 400 });
+    const { ticketId } = await driveTicketToAcceptedQuotation();
+    const { depositNotice: draft } = await api.depositNotices.createDraft(ticketId, { notes: [] });
+    await api.tickets.confirmCustomer(ticketId);
+    await api.depositNotices.issue(draft.id);
+    await expect(api.depositNotices.update(draft.id, { depositPercent: 0 }))
+      .rejects.toMatchObject({ status: 400 });
+  });
+
+  // Mirrors the stale-save check (DepositNoticeRepository#update): a save carrying an older
+  // updatedAt than the stored one is refused; one carrying the current stamp, or none, saves.
+  it('refuses a save whose expectedUpdatedAt is stale', async () => {
+    const { ticketId } = await driveTicketToAcceptedQuotation();
+    const { depositNotice: draft } = await api.depositNotices.createDraft(ticketId, { notes: [] });
+    const { depositNotice: savedByA } = await api.depositNotices.update(draft.id,
+      { depositPercent: 0.4, items: draft.items, expectedUpdatedAt: draft.updatedAt });
+
+    await expect(api.depositNotices.update(draft.id,
+      { depositPercent: 0.3, items: draft.items, expectedUpdatedAt: draft.updatedAt }))
+      .rejects.toMatchObject({ status: 409, message: 'ใบแจ้งรับมัดจำนี้ถูกแก้ไขโดยผู้ใช้อื่น กรุณาโหลดข้อมูลใหม่แล้วลองอีกครั้ง' });
+    expect((await api.depositNotices.get(draft.id)).depositNotice.depositPercent).toBe(0.4);
+
+    await api.depositNotices.update(draft.id, { depositPercent: 0.3, expectedUpdatedAt: savedByA.updatedAt });
+    expect((await api.depositNotices.get(draft.id)).depositNotice.depositPercent).toBe(0.3);
+  });
+
+  // Mirrors DepositNoticeService.update/issue: sales only (requireRole), then the deal owner.
+  it('refuses update and issue to a sales rep who does not own the deal, and to a non-sales role', async () => {
+    const { ticketId } = await driveTicketToAcceptedQuotation();
+    const { depositNotice: draft } = await api.depositNotices.createDraft(ticketId, { notes: [] });
+    await api.tickets.confirmCustomer(ticketId);
+
+    await api.auth.login({ email: 'sales2@glr.co.th', password: 'demo1234' });
+    await expect(api.depositNotices.update(draft.id, { customerName: 'x' }))
+      .rejects.toMatchObject({ status: 403, message: 'ไม่มีสิทธิ์เข้าถึงรายการนี้' });
+    await expect(api.depositNotices.issue(draft.id)).rejects.toMatchObject({ status: 403 });
+    await api.auth.login({ role: 'sales_manager' });
+    await expect(api.depositNotices.update(draft.id, { customerName: 'x' })).rejects.toMatchObject({ status: 403 });
+    await expect(api.depositNotices.issue(draft.id)).rejects.toMatchObject({ status: 403 });
+
+    await api.auth.login({ role: 'sales' });
+    const { depositNotice: reread } = await api.depositNotices.get(draft.id);
+    expect(reread.status).toBe('DRAFT');
+    expect(reread.customerName).toBe(draft.customerName);
+  });
+
+  it('on an ISSUED notice is refused with 409 and changes nothing; no second draft on either route', async () => {
+    const { ticketId } = await driveTicketToAcceptedQuotation();
+    const { depositNotice: draft } = await api.depositNotices.createDraft(ticketId, { notes: [] });
+    const { depositNotice: secondDraft } = await api.depositNotices.createDraft(ticketId, { notes: [] });
+    await api.tickets.confirmCustomer(ticketId);
+    const { depositNotice: issued } = await api.depositNotices.issue(draft.id);
+
+    // Owner ruling 2026-10-23: a second draft that predates the issue takes no number either.
+    await expect(api.depositNotices.issue(secondDraft.id)).rejects.toMatchObject({
+      status: 409,
+      message: `ดีลนี้ออกใบแจ้งรับมัดจำเลขที่ ${issued.docNumber} แล้ว จึงออกฉบับร่างนี้ไม่ได้`,
+    });
+    const { depositNotice: secondReread } = await api.depositNotices.get(secondDraft.id);
+    expect(secondReread.status).toBe('DRAFT');
+    expect(secondReread.docNumber).toBeNull();
+    expect((await api.depositNotices.get(issued.id)).depositNotice.status).toBe('ISSUED');
+
+    await expect(api.depositNotices.update(issued.id, { depositPercent: 0.4 }))
+      .rejects.toMatchObject({ status: 409 });
+    const { depositNotice: reread } = await api.depositNotices.get(issued.id);
+    expect(reread.depositPercent).toBe(issued.depositPercent);
+    expect(reread.depositAmount).toBe(issued.depositAmount);
+
+    // Owner ruling 2026-10-23 (DepositNoticeService.createDraftFromQuotation): one notice per deal.
+    const message = `ดีลนี้ออกใบแจ้งรับมัดจำเลขที่ ${issued.docNumber} แล้ว จึงสร้างฉบับร่างใหม่ไม่ได้`;
+    await expect(api.depositNotices.createDraft(ticketId, {})).rejects.toMatchObject({ status: 409, message });
+    const prId = (await api.pricingRequests.listForTicket(ticketId)).items
+      .find((pr) => pr.status === 'QUOTATION_ACCEPTED').id;
+    await expect(api.pricingRequests.createDepositNoticeFromQuotation(prId, {})).rejects.toMatchObject({ status: 409, message });
+    expect((await api.depositNotices.listByTicket(ticketId)).depositNotices).toHaveLength(2); // no third
+  });
+});
+
 // GLA-32 (2026-09-19): mirrors DepositNoticeService.issue's account-role notification (backend
 // backend/src/main/java/th/co/glr/hr/deposit/DepositNoticeService.java) — issuing a deposit
 // notice notifies the account role, in-app, so account picks up the deal here rather than
@@ -507,9 +620,11 @@ describe('mock deposit-percent defaults match the Java PDFs', () => {
 describe('mockApi.depositNotices.issue refuses a 0-baht notice', () => {
   it('409s, and the draft stays DRAFT with no number', async () => {
     const { ticketId } = await driveTicketToNewEngineAcceptedQuotation({ depositPercent: 30 });
-    // create ignores a typed percent now; the mock's update still honours one, which stands in for the Java test's jdbc insert.
+    // update refuses a 0% now, so a free line (net price 0) stands in for the Java test's jdbc insert.
     const { depositNotice: created } = await api.depositNotices.createDraft(ticketId, {});
-    const { depositNotice: draft } = await api.depositNotices.update(created.id, { depositPercent: 0 });
+    const { depositNotice: draft } = await api.depositNotices.update(created.id, {
+      items: [{ seq: 1, description: 'Free item', qty: 2, unit: 'แผ่น', unitPrice: 0, netUnitPrice: 0 }],
+    });
     expect(draft.depositAmount).toBe(0);
     await expect(api.depositNotices.issue(draft.id))
       .rejects.toMatchObject({ status: 409, message: expect.stringContaining('0 บาท') });
diff --git a/frontend/src/api/mockApi.js b/frontend/src/api/mockApi.js
index 26632a528..3cc13d9d7 100644
--- a/frontend/src/api/mockApi.js
+++ b/frontend/src/api/mockApi.js
@@ -1441,18 +1441,36 @@ function mockDepositNoticeItemsFromQuotation(items) {
 // Mirrors DepositNoticeRepository.findDealQuotationItems. Values are read off the stored row,
 // never recomputed (label excepted — see below).
 function mockDepositNoticeItemsFromDealQuotation(row) {
-  return row.items.map((item, idx) => {
+  // DepositNoticeRepository#foldAdjustments: an ADJUSTMENT row (qty -1) is no deposit line; its
+  // amount is spread over the goods lines by amount, each share and each new net price 2 dp (no
+  // remainder on a last line: the notice total is its own 2 dp lines). A line keeps the quotation's
+  // own discount wording and gains the folded discount after it.
+  // ponytail: the mock computes no % adjustment amount (MOCK_NOT_COMPUTED), so that row is only dropped.
+  const goods = row.items.filter((item) => item.lineType !== 'ADJUSTMENT');
+  const adjustment = row.items.filter((item) => item.lineType === 'ADJUSTMENT')
+    .reduce((sum, item) => sum + (Number(item.netUnitPrice) || 0) * Number(item.quantity), 0);
+  const amountOf = (item) => item.netUnitPrice * item.quantity;
+  const total = goods.reduce((sum, item) => sum + amountOf(item), 0);
+  return goods.map((item, idx) => {
+    let netUnitPrice = item.netUnitPrice;
+    if (adjustment && total && amountOf(item)) {
+      const share = round2((adjustment * amountOf(item)) / total);
+      netUnitPrice = round2((amountOf(item) + share) / item.quantity);
+    }
     // Display label only: the mock stores no sales_discount, so this restates the column Java reads
     // (DealQuotationRepository#itemParams writes it as unitPrice − netUnitPrice).
     const salesDiscount = round2(item.unitPrice - item.netUnitPrice);
+    const folded = round2(item.netUnitPrice - netUnitPrice);
+    const own = salesDiscount > 0 ? `ส่วนลด ${salesDiscount} ต่อหน่วย` : null;
+    const extra = folded > 0 ? `ส่วนลดพิเศษ ${folded} ต่อหน่วย` : null;
     return {
       seq: item.seq ?? idx + 1,
       description: item.descriptionLine?.trim() ? item.descriptionLine : 'รายการสินค้า',
       qty: item.quantity,
       unit: item.unit?.trim() ? item.unit : 'หน่วย',
       unitPrice: item.unitPrice,
-      discountLabel: salesDiscount > 0 ? `ส่วนลด ${salesDiscount} ต่อหน่วย` : null,
-      netUnitPrice: item.netUnitPrice,
+      discountLabel: own && extra ? `${own} + ${extra}` : own ?? extra,
+      netUnitPrice,
     };
   });
 }
@@ -2417,6 +2435,13 @@ function stripCeoPriceModeFields(decision, user) {
   };
 }
 
+// Mirrors DepositNoticeService.createDraftFromQuotation (both create routes): one deposit notice
+// per deal, so no new draft while one is ISSUED (owner ruling 2026-10-23).
+function requireNoIssuedDepositNotice(ticketId) {
+  const issued = mockDepositNotices.find((d) => d.ticketId === Number(ticketId) && d.status === 'ISSUED');
+  if (issued) fail(`ดีลนี้ออกใบแจ้งรับมัดจำเลขที่ ${issued.docNumber} แล้ว จึงสร้างฉบับร่างใหม่ไม่ได้`, 409);
+}
+
 function buildMockDoc(doc) {
   const items = doc.items ?? [];
   const depositPct = doc.depositPercent ?? 0.5;
@@ -13316,6 +13341,7 @@ export const api = {
       const user = hasRole('sales');
       const ticket = findTicketRaw(Number(ticketId));
       if (ticket.createdById !== user.id) fail('ไม่มีสิทธิ์เข้าถึงรายการนี้', 403);
+      requireNoIssuedDepositNotice(ticket.id);
       // Phase 1 lifecycle gate (mirrors DepositNoticeService.createDraft).
       requireActive(ticket);
       if (!['approved', 'quotation_issued', 'document_issued'].includes(ticket.status)) fail('ดีลต้องได้รับการอนุมัติก่อน', 409);
@@ -13391,9 +13417,25 @@ export const api = {
 
     async update(docId, payload) {
       requireSession();
+      // DepositNoticeDraftRequest's @DecimalMin/@DecimalMax: @Valid runs before any lookup.
+      const sent = payload.depositPercent == null ? null : Number(payload.depositPercent) * 100;
+      if (sent != null && sent > 100) fail('depositPercent เปอร์เซ็นต์มัดจำต้องไม่เกิน 100', 400);
+      if (sent != null && !(sent > 0)) fail('depositPercent เปอร์เซ็นต์มัดจำต้องมากกว่า 0', 400);
+      // DepositNoticeService.update: sales only, a DRAFT, the deal owner, then the % rules.
+      const user = hasRole('sales');
       const doc = mockDepositNotices.find((d) => d.id === Number(docId));
       if (!doc) fail('ไม่พบใบแจ้งรับมัดจำนี้', 404);
       if (doc.status !== 'DRAFT') fail('ใบแจ้งรับมัดจำนี้ไม่ได้อยู่ในสถานะร่าง (DRAFT)', 409);
+      if (findTicketRaw(doc.ticketId).createdById !== user.id) fail('ไม่มีสิทธิ์เข้าถึงรายการนี้', 403);
+      const stored = Number(doc.depositPercent) * 100;
+      const pct = sent ?? stored;
+      if (!(pct > 0)) fail('เปอร์เซ็นต์มัดจำต้องมากกว่า 0', 400);
+      // A stored legacy fraction sent back unchanged still saves.
+      if (pct !== stored && Math.abs(pct - Math.round(pct)) > 1e-9) fail('เปอร์เซ็นต์มัดจำต้องเป็นจำนวนเต็ม', 400);
+      // DepositNoticeRepository#update: a save over someone else's newer one is refused.
+      if (payload.expectedUpdatedAt != null && payload.expectedUpdatedAt !== doc.updatedAt) {
+        fail('ใบแจ้งรับมัดจำนี้ถูกแก้ไขโดยผู้ใช้อื่น กรุณาโหลดข้อมูลใหม่แล้วลองอีกครั้ง', 409);
+      }
       Object.assign(doc, {
         customerName:    payload.customerName    ?? doc.customerName,
         customerTaxId:   payload.customerTaxId   ?? doc.customerTaxId,
@@ -13403,7 +13445,8 @@ export const api = {
         depositPercent:  payload.depositPercent  ?? doc.depositPercent,
         notes:           payload.notes           ?? doc.notes,
         items:           payload.items?.length ? payload.items : doc.items,
-        updatedAt:       new Date().toISOString(),
+        // Strictly later than the stored stamp, so two saves in one millisecond still differ.
+        updatedAt:       new Date(Math.max(Date.now(), (Date.parse(doc.updatedAt) || 0) + 1)).toISOString(),
       });
       const updated = buildMockDoc(doc);
       Object.assign(doc, updated);
@@ -13419,12 +13462,23 @@ export const api = {
       return mockPreviewHtml(buildMockDoc(doc));
     },
 
-    async issue(docId) {
+    async issue(docId, payload) {
       const user = requireSession();
       const doc = mockDepositNotices.find((d) => d.id === Number(docId));
       if (!doc) fail('ไม่พบใบแจ้งรับมัดจำนี้', 404);
       if (doc.status !== 'DRAFT') fail('ไม่ได้อยู่ในสถานะร่าง (DRAFT)', 409);
       const ticket = findTicketRaw(doc.ticketId);
+      // DepositNoticeService.issue: sales only, the deal owner, and a stored % the document can print.
+      if (user.role !== 'sales' || ticket.createdById !== user.id) fail('ไม่มีสิทธิ์เข้าถึงรายการนี้', 403);
+      const pct = Number(doc.depositPercent) * 100;
+      if (!(pct > 0 && pct <= 100) || Math.abs(pct - Math.round(pct)) > 1e-9) {
+        fail(`ใบแจ้งรับมัดจำนี้มีเปอร์เซ็นต์มัดจำ ${+pct.toFixed(4)}% จึงออกเอกสารไม่ได้ (ต้องเป็นจำนวนเต็ม 1–100)`, 409);
+      }
+
+      // Mirrors DepositNoticeService.issue's one-notice-per-deal refusal (owner ruling 2026-10-23).
+      // Checked before the payment-state gate: the mock cannot re-issue from DEPOSIT_NOTICE_ISSUED.
+      const other = mockDepositNotices.find((d) => d.ticketId === doc.ticketId && d.id !== doc.id && d.status === 'ISSUED');
+      if (other) fail(`ดีลนี้ออกใบแจ้งรับมัดจำเลขที่ ${other.docNumber} แล้ว จึงออกฉบับร่างนี้ไม่ได้`, 409);
 
       // Mirrors DepositNoticeService.issue: the document IS the payment-track step.
       // Requires a customer-confirmed quotation; advances paymentStatus and leaves
@@ -13436,9 +13490,10 @@ export const api = {
       if (!(Number(doc.depositAmount) > 0)) fail('ใบแจ้งรับมัดจำนี้มียอดมัดจำ 0 บาท จึงออกเอกสารไม่ได้', 409);
       // Phase 1 lifecycle gate (mirrors DepositNoticeService.requireActiveLifecycle).
       requireActive(ticket);
-
-      // Supersede previous issued docs
-      mockDepositNotices.forEach((d) => { if (d.ticketId === doc.ticketId && d.id !== doc.id && d.status === 'ISSUED') d.status = 'SUPERSEDED'; });
+      // DepositNoticeRepository#issue: the draft was saved after the caller read it.
+      if (payload?.expectedUpdatedAt != null && payload.expectedUpdatedAt !== doc.updatedAt) {
+        fail('ใบแจ้งรับมัดจำนี้ถูกแก้ไขโดยผู้ใช้อื่น กรุณาโหลดข้อมูลใหม่แล้วลองอีกครั้ง', 409);
+      }
 
       const thaiYear = new Date().getFullYear() + 543;
       doc.docNumber = `GLRD${String(thaiYear).slice(-2)}${String(mockDocNumberSeq++).padStart(3,'0')}`;
@@ -16258,6 +16313,7 @@ export const api = {
       if (!accepted && !newEngine) fail('ยังไม่มีใบเสนอราคาที่ลูกค้ายอมรับสำหรับคำขอราคานี้', 409);
       // Mirrors the zero-deposit refusal: a 0% ("ไม่รับมัดจำ") quotation has nothing to bill.
       if (newEngine?.depositPercent === 0) fail(mockZeroDepositRefusal(newEngine.number), 409);
+      requireNoIssuedDepositNotice(ticket.id);
       const reference = (accepted ?? newEngine).number;
       const items = accepted
         ? mockDepositNoticeItemsFromQuotation(accepted.items)
diff --git a/frontend/src/api/mockApi.promoteToDeal.test.js b/frontend/src/api/mockApi.promoteToDeal.test.js
index c55b599f3..ff9bb889f 100644
--- a/frontend/src/api/mockApi.promoteToDeal.test.js
+++ b/frontend/src/api/mockApi.promoteToDeal.test.js
@@ -35,9 +35,9 @@ async function quotationOnlyTicket() {
   return ticket.summary.id;
 }
 
-async function approvedQuotation(ticketId) {
+async function approvedQuotation(ticketId, items = [TILE, PLAIN, ADJUSTMENT]) {
   await asRole('sales');
-  const { quotation: draft } = await api.dealQuotations.create(ticketId, { recipientType: 'DESIGNER', items: [TILE, PLAIN, ADJUSTMENT] });
+  const { quotation: draft } = await api.dealQuotations.create(ticketId, { recipientType: 'DESIGNER', items });
   await api.dealQuotations.submit(draft.id);
   await asRole('sales_manager');
   const { quotation } = await api.dealQuotations.approve(draft.id);
@@ -126,6 +126,27 @@ describe('mock dealQuotations.promoteToDeal (GLA-136)', () => {
     expect(await listIds()).toContain(ghost);
   });
 
+  // Owner ruling 2026-10-23 (DepositNoticeRepository#foldAdjustments): the deposit draft carries no
+  // qty -1 ส่วนลดพิเศษ row; a flat 95 is spread by line amount (TILE 8,500 takes 85, PLAIN 1,000
+  // takes 10), so the subtotal is the quotation's 9,405. The mock computes no % adjustment amount
+  // (MOCK_NOT_COMPUTED), so a % row is only dropped.
+  it('the deposit draft folds a flat ส่วนลดพิเศษ into the goods lines and drops a % one', async () => {
+    const ghost = await quotationOnlyTicket();
+    const flat = await approvedQuotation(ghost, [TILE, PLAIN, { lineType: 'ADJUSTMENT', description: 'ส่วนลดพิเศษ', adjustmentAmount: 95 }]);
+    await api.dealQuotations.promoteToDeal(flat.id);
+    const { depositNotice } = await api.depositNotices.createDraft(ghost, {});
+    expect(depositNotice.items.map((i) => [i.qty, i.unitPrice, i.netUnitPrice, i.discountLabel])).toEqual([
+      [10, 850, 841.5, 'ส่วนลดพิเศษ 8.5 ต่อหน่วย'],
+      [2, 500, 495, 'ส่วนลดพิเศษ 5 ต่อหน่วย'],
+    ]);
+    expect(depositNotice.subtotal).toBe(9405);
+
+    const other = await quotationOnlyTicket();
+    await api.dealQuotations.promoteToDeal((await approvedQuotation(other)).id);
+    const { depositNotice: pctDraft } = await api.depositNotices.createDraft(other, {});
+    expect(pctDraft.items.map((i) => i.qty)).toEqual([10, 2]);
+  });
+
   it('a replay is idempotent — same deal, no second event', async () => {
     const ghost = await quotationOnlyTicket();
     const approved = await approvedQuotation(ghost);
diff --git a/frontend/src/features/deposits/DepositNoticePage.jsx b/frontend/src/features/deposits/DepositNoticePage.jsx
index a8d374b24..9e5268354 100644
--- a/frontend/src/features/deposits/DepositNoticePage.jsx
+++ b/frontend/src/features/deposits/DepositNoticePage.jsx
@@ -14,6 +14,7 @@ import { StatusBadge } from '../../components/common/StatusBadge.jsx';
 import { fieldErrorId } from '../../components/common/FormField.jsx';
 import { depositNoticeStatusLabel, formatThaiDate } from '../../utils/format.js';
 import { downloadBlob } from '../../utils/download.js';
+import { round2 } from '../quotations/quotationMeta.js';
 
 function money(v) {
   if (v == null) return '—';
@@ -35,6 +36,43 @@ function formatVatPercent(rate) {
   return String(Math.round(Number(rate) * 100 * 100) / 100);
 }
 
+// A line's net unit price: 0 is a real price (a 100%-discounted line), only a missing one falls
+// back to the unit price.
+function lineNet(item) {
+  return Number(item.netUnitPrice ?? item.unitPrice) || 0;
+}
+
+// An untouched เพิ่มรายการ row (or one emptied again): no description and nothing to bill. Left
+// out of the save (the backend refuses a line without a description) and of the issue checks.
+const NO_ITEMS_MESSAGE = 'กรุณาเพิ่มรายการสินค้าอย่างน้อย 1 รายการ';
+
+function isBlankRow(item) {
+  return !String(item.description ?? '').trim() && !(lineNet(item) * (Number(item.qty) || 0));
+}
+
+/** The confirm-before-issue amounts, shared by this editor and DealDepositPanel's ออกเอกสาร. */
+export function DepositIssueSummary({ customerName, depositPercent, deposit, vatPercent, vat, total }) {
+  return (
+    <div className="flex flex-col gap-2">
+      <p className="confirm-dialog-message text-text-secondary leading-normal m-0">
+        ตรวจสอบยอดเงินก่อนออกเอกสารให้ <strong>{customerName || 'ลูกค้า'}</strong> — <strong>หลังจากนี้จะไม่สามารถแก้ไขได้</strong>
+      </p>
+      <div className="flex justify-between border-t border-border pt-2 text-sm">
+        <span className="text-icon-muted">ขอรับเงินมัดจำ ({Math.round(Number(depositPercent) * 100)}%)</span>
+        <code className="font-mono">{money(deposit)} บาท</code>
+      </div>
+      <div className="flex justify-between text-sm">
+        <span className="text-icon-muted">ภาษีมูลค่าเพิ่ม {formatVatPercent(vatPercent)}%</span>
+        <code className="font-mono">{money(vat)} บาท</code>
+      </div>
+      <div className="flex justify-between text-md font-bold">
+        <span>รวมเป็นเงินที่ต้องชำระ</span>
+        <code className="font-mono">{money(total)} บาท</code>
+      </div>
+    </div>
+  );
+}
+
 // ── validation (UX-03) ──────────────────────────────────────────────────────
 // This gate fires ONLY from handleIssue() — never from handleSave() or the
 // preview path. This is a draft editor: users save partial drafts
@@ -69,7 +107,7 @@ function makeLineItemSchema(rowNumber) {
  * handleIssue() can scroll/focus the first one without depending on zod's
  * internal issue ordering.
  */
-function validateIssueForm({ customerName, items, total }) {
+function validateIssueForm({ customerName, items, total, depositPercent }) {
   const errors = {};
   const order = [];
 
@@ -79,11 +117,12 @@ function validateIssueForm({ customerName, items, total }) {
     order.push('customerName');
   }
 
-  if (items.length === 0) {
-    errors.items = 'กรุณาเพิ่มรายการสินค้าอย่างน้อย 1 รายการ';
+  if (items.every(isBlankRow)) {
+    errors.items = NO_ITEMS_MESSAGE;
     order.push('items');
   } else {
     items.forEach((item, index) => {
+      if (isBlankRow(item)) return;
       const result = makeLineItemSchema(index + 1).safeParse(item);
       if (!result.success) {
         for (const issue of result.error.issues) {
@@ -95,6 +134,14 @@ function validateIssueForm({ customerName, items, total }) {
     });
   }
 
+  // The % sits after the items on screen. A whole 1–100 is what the backend issues; outside it the
+  // ฿0 rule below would blame the unit price (0%) or the backend would refuse behind the dialog (150%).
+  const percent = depositPercent === '' ? NaN : Math.round(Number(depositPercent) * 100);
+  if (!(percent >= 1 && percent <= 100)) {
+    errors.depositPercent = 'กรุณากรอก % มัดจำเป็นจำนวนเต็ม 1–100';
+    order.push('depositPercent');
+  }
+
   // Rule 4: issuing a ฿0 deposit notice is meaningless and would still
   // advance the ticket's payment track. Only checked once the rules above
   // are otherwise satisfied — a ฿0 total caused by missing item data is
@@ -229,7 +276,8 @@ export function DepositNoticePage({ ticketId, onBack, onNavigateTickets, showToa
       customerAddress: address,
       projectName:     d.projectName   ?? '',
       reference:       d.reference     ?? '',
-      depositPercent:  d.depositPercent ?? 0.5,
+      // As stored (null -> blank, which saves as "keep"): a save of another field must not rewrite it.
+      depositPercent:  d.depositPercent ?? '',
       notes:           d.notes         ?? [],
       items:           (d.items ?? []).map((it) => ({ ...it })),
     });
@@ -240,6 +288,10 @@ export function DepositNoticePage({ ticketId, onBack, onNavigateTickets, showToa
   // background refetch of the same doc (e.g. a save doesn't bump
   // version/status, so no reseed fires and in-flight edits aren't clobbered).
   const docSeedKey = doc ? `${doc.id}:${doc.version}:${doc.status}` : null;
+  // The draft's updatedAt as last read from the server (the list, or this page's own save):
+  // sent as expectedUpdatedAt, so a save over someone else's newer one is refused (409).
+  const stampRef = useRef(null);
+  useEffect(() => { stampRef.current = doc?.updatedAt ?? null; }, [doc?.updatedAt]);
   useEffect(() => {
     if (doc) populateForm(doc, customers);
     // A reseed means a different document identity (or the same one flipping
@@ -253,6 +305,22 @@ export function DepositNoticePage({ ticketId, onBack, onNavigateTickets, showToa
     return queryClient.invalidateQueries({ queryKey: queryKeys.depositNotices(ticketId) });
   }
 
+  async function saveDraft() {
+    const res = await api.depositNotices.update(doc.id, buildPayload());
+    stampRef.current = res?.depositNotice?.updatedAt ?? stampRef.current;
+    return res;
+  }
+
+  // A 409 means the server's copy moved on (saved elsewhere, or issued): reload it, form included,
+  // and show the server's message.
+  async function onSaveError(err, fallback) {
+    showToast('error', err.message || fallback);
+    if (err.status !== 409) return;
+    const { data } = await depositNoticesQuery.refetch();
+    const fresh = (data ?? []).find((d) => d.id === doc.id);
+    if (fresh) populateForm(fresh, customers);
+  }
+
   const createDraftMutation = useMutation({
     // Prefer the pricing-request-chain endpoint (createDepositNoticeFromQuotation) when this
     // deal has a pricing request whose customer quotation was accepted — that route sources
@@ -274,10 +342,9 @@ export function DepositNoticePage({ ticketId, onBack, onNavigateTickets, showToa
       } catch {
         acceptedPricingRequestId = null;
       }
-      // depositPercent is deliberately NOT sent on either branch below (owner ruling,
-      // 2026-09-29): the backend always ignores a caller-supplied value now and re-sources it
-      // from the ticket's own quotation (see DepositNoticeService.createDraft), falling back to
-      // 0.50 only when there is no quotation to read it from at all.
+      // depositPercent is not sent on either branch below: the backend picks the new draft's
+      // percent (DepositNoticeService.createDraftFromQuotation; findGoverningQuotation, #1170).
+      // Sales changes it on the draft.
       if (acceptedPricingRequestId != null) {
         return api.pricingRequests.createDepositNoticeFromQuotation(acceptedPricingRequestId, {});
       }
@@ -294,34 +361,42 @@ export function DepositNoticePage({ ticketId, onBack, onNavigateTickets, showToa
   }
 
   const saveMutation = useMutation({
-    mutationFn: () => api.depositNotices.update(doc.id, buildPayload()),
+    mutationFn: saveDraft,
     onSuccess: () => {
       showToast('success', 'บันทึกแล้ว');
       invalidateDepositNotices();
     },
-    onError: (err) => showToast('error', err.message || 'บันทึกไม่สำเร็จ'),
+    onError: (err) => onSaveError(err, 'บันทึกไม่สำเร็จ'),
   });
 
+  // Blank rows are not sent and an empty `items` makes the backend keep the stored lines, so a form
+  // whose rows were all cleared would "save" and bring the old lines back: refuse it instead.
+  function refusesClearedItems() {
+    if (!(doc.items?.length > 0 && form.items.every(isBlankRow))) return false;
+    setFieldErrors({ items: NO_ITEMS_MESSAGE });
+    return true;
+  }
+
   function handleSave() {
-    if (!doc) return;
+    if (!doc || refusesClearedItems()) return;
     saveMutation.mutate();
   }
 
   const previewMutation = useMutation({
     mutationFn: async () => {
       // Save first, then preview.
-      await api.depositNotices.update(doc.id, buildPayload());
+      await saveDraft();
       return api.depositNotices.preview(doc.id);
     },
     onSuccess: (html) => {
       setPreview(html);
       invalidateDepositNotices();
     },
-    onError: (err) => showToast('error', err.message || 'Preview ไม่สำเร็จ'),
+    onError: (err) => onSaveError(err, 'Preview ไม่สำเร็จ'),
   });
 
   function handlePreview() {
-    if (!doc) return;
+    if (!doc || refusesClearedItems()) return;
     previewMutation.mutate();
   }
 
@@ -331,7 +406,9 @@ export function DepositNoticePage({ ticketId, onBack, onNavigateTickets, showToa
     // sure?" for something that's then going to fail. `total` is read here
     // (never written) from the money-math block below; see the HARD
     // CONSTRAINT comment on that block.
-    const { errors, order } = validateIssueForm({ customerName: form.customerName, items: form.items, total });
+    const { errors, order } = validateIssueForm({
+      customerName: form.customerName, items: form.items, total, depositPercent: form.depositPercent,
+    });
     if (order.length > 0) {
       setFieldErrors(errors);
       const node = fieldRefs.current[order[0]];
@@ -350,8 +427,8 @@ export function DepositNoticePage({ ticketId, onBack, onNavigateTickets, showToa
   const issueMutation = useMutation({
     mutationFn: async () => {
       // Save first.
-      await api.depositNotices.update(doc.id, buildPayload());
-      return api.depositNotices.issue(doc.id);
+      await saveDraft();
+      return api.depositNotices.issue(doc.id, { expectedUpdatedAt: stampRef.current });
     },
     onSuccess: (res) => {
       showToast('success', `ออกเอกสาร ${res.depositNotice.docNumber} เรียบร้อย`);
@@ -363,7 +440,10 @@ export function DepositNoticePage({ ticketId, onBack, onNavigateTickets, showToa
       queryClient.invalidateQueries({ queryKey: ['tickets', 'list'] });
       queryClient.invalidateQueries({ queryKey: queryKeys.ticketDetail(ticketId) });
     },
-    onError: (err) => showToast('error', err.message || 'ออกเอกสารไม่สำเร็จ'),
+    onError: (err) => {
+      setConfirmIssue(false);
+      onSaveError(err, 'ออกเอกสารไม่สำเร็จ');
+    },
   });
 
   function confirmIssueDocument() {
@@ -377,10 +457,13 @@ export function DepositNoticePage({ ticketId, onBack, onNavigateTickets, showToa
   function setField(key, value) {
     setForm((f) => ({ ...f, [key]: value }));
     if (key === 'customerName') clearFieldError('customerName');
-    // The deposit % toggle feeds directly into `deposit`/`total` below —
+    // The deposit % field feeds directly into `deposit`/`total` below —
     // clear a stale "total must be > 0" error so it can be re-checked fresh
     // on the next issue attempt.
-    if (key === 'depositPercent') clearFieldError('total');
+    if (key === 'depositPercent') {
+      clearFieldError('total');
+      clearFieldError('depositPercent');
+    }
   }
 
   function selectCustomer(c) {
@@ -450,31 +533,31 @@ export function DepositNoticePage({ ticketId, onBack, onNavigateTickets, showToa
       customerAddress: form.customerAddress,
       projectName:     form.projectName,
       reference:       form.reference,
-      depositPercent:  Number(form.depositPercent),
+      // A cleared field keeps the stored % (null) rather than failing the whole save at 0.
+      depositPercent:  form.depositPercent === '' ? null : Number(form.depositPercent),
       notes:           form.notes,
-      items: form.items.map((it, idx) => ({
+      expectedUpdatedAt: stampRef.current,
+      items: form.items.filter((it) => !isBlankRow(it)).map((it, idx) => ({
         seq:          idx + 1,
         description:  it.description ?? '',
         qty:          Number(it.qty) || 0,
         unit:         it.unit ?? 'แผ่น',
         unitPrice:    Number(it.unitPrice) || 0,
         discountLabel: it.discountLabel ?? null,
-        netUnitPrice: Number(it.netUnitPrice) || Number(it.unitPrice) || 0,
+        netUnitPrice: lineNet(it),
       })),
     };
   }
 
-  // Recalculate summary from form items
-  const subtotal = form.items.reduce((sum, it) => {
-    const net = Number(it.netUnitPrice) || Number(it.unitPrice) || 0;
-    return sum + net * (Number(it.qty) || 0);
-  }, 0);
-  const deposit = subtotal * Number(form.depositPercent || 0.5);
+  // Recalculate summary from form items, rounding each step to the satang as
+  // DepositNoticeRepository does (HALF_UP), so the screen matches the stored document.
+  const subtotal = round2(form.items.reduce((sum, it) => sum + lineNet(it) * (Number(it.qty) || 0), 0));
+  const deposit = round2(subtotal * (Number(form.depositPercent) || 0));
   // Issue #756: the served document's own vatPercent always wins once one exists — only
   // before that (no `doc` yet) does this fall back to FALLBACK_VAT_PERCENT above.
   const vatPercent = Number(doc?.vatPercent ?? FALLBACK_VAT_PERCENT);
-  const vat = deposit * vatPercent;
-  const total = deposit + vat;
+  const vat = round2(deposit * vatPercent);
+  const total = round2(deposit + vat);
 
   if (loading) {
     return (
@@ -822,21 +905,24 @@ export function DepositNoticePage({ ticketId, onBack, onNavigateTickets, showToa
               aria-describedby={fieldErrors.total ? fieldErrorId('doc-summary-panel') : undefined}
               className="px-4.5 py-3.5"
             >
-              {/*
-                Owner rulings (2026-09-29, 2026-10-23): the deposit % is what the source
-                quotation's PDF printed (legacy 50%, new-engine its own, blank 30%; 50% with no
-                live quotation) and is never editable at the deposit-notice stage: createDraft
-                never reads a client-supplied value and update keeps the draft's stored one. The
-                30/50/70/100% preset buttons this used to be are gone; this is now a plain
-                read-only label, shown regardless of isIssued since there is no draft-only
-                editable state left to distinguish.
-              */}
-              <div className="mb-3 text-xs">
-                <span className="block text-icon-muted">% มัดจำ</span>
-                <span className="mt-1 inline-block rounded-[6px] border border-border-muted bg-surface-subtle px-3 py-1 text-sm text-text-secondary">
-                  {Math.round(Number(form.depositPercent) * 100)}%
-                </span>
-              </div>
+              {/* Owner ruling 2026-10-23: the % starts from the quotation; sales may change it on
+                  a DRAFT (whole number on screen, a fraction in the payload). Read-only once issued. */}
+              <label className="mb-3 block text-xs">
+                % มัดจำ
+                <input type="number" min="1" max="100" step="1" disabled={isIssued}
+                  id="doc-deposit-percent"
+                  ref={(el) => { fieldRefs.current.depositPercent = el; }}
+                  value={form.depositPercent === '' ? '' : Math.round(Number(form.depositPercent) * 100)}
+                  onChange={(e) => setField('depositPercent', e.target.value === '' ? '' : Math.round(Number(e.target.value)) / 100)}
+                  aria-invalid={fieldErrors.depositPercent ? true : undefined}
+                  aria-describedby={fieldErrors.depositPercent ? fieldErrorId('doc-deposit-percent') : undefined}
+                  className="text-right" />
+              </label>
+              {fieldErrors.depositPercent ? (
+                <p id={fieldErrorId('doc-deposit-percent')} role="alert" className="mx-0 mb-2 mt-0 text-xs font-bold text-danger">
+                  {fieldErrors.depositPercent}
+                </p>
+              ) : null}
               {[
                 { label: 'รวมเป็นเงิน', value: subtotal },
                 { label: `ขอรับเงินมัดจำ (${Math.round(Number(form.depositPercent) * 100)}%)`, value: deposit },
@@ -900,23 +986,8 @@ export function DepositNoticePage({ ticketId, onBack, onNavigateTickets, showToa
         open={confirmIssue}
         title="ยืนยันการออกเอกสาร"
         message={(
-          <div className="flex flex-col gap-2">
-            <p className="confirm-dialog-message text-text-secondary leading-normal m-0">
-              ตรวจสอบยอดเงินก่อนออกเอกสารให้ <strong>{form.customerName || 'ลูกค้า'}</strong> — <strong>หลังจากนี้จะไม่สามารถแก้ไขได้</strong>
-            </p>
-            <div className="flex justify-between border-t border-border pt-2 text-sm">
-              <span className="text-icon-muted">ขอรับเงินมัดจำ ({Math.round(Number(form.depositPercent) * 100)}%)</span>
-              <code className="font-mono">{money(deposit)} บาท</code>
-            </div>
-            <div className="flex justify-between text-sm">
-              <span className="text-icon-muted">ภาษีมูลค่าเพิ่ม {formatVatPercent(vatPercent)}%</span>
-              <code className="font-mono">{money(vat)} บาท</code>
-            </div>
-            <div className="flex justify-between text-md font-bold">
-              <span>รวมเป็นเงินที่ต้องชำระ</span>
-              <code className="font-mono">{money(total)} บาท</code>
-            </div>
-          </div>
+          <DepositIssueSummary customerName={form.customerName} depositPercent={form.depositPercent}
+            deposit={deposit} vatPercent={vatPercent} vat={vat} total={total} />
         )}
         confirmLabel="ออกเอกสาร"
         busy={saving}
diff --git a/frontend/src/features/deposits/DepositNoticePage.test.jsx b/frontend/src/features/deposits/DepositNoticePage.test.jsx
index b885e40dc..040901277 100644
--- a/frontend/src/features/deposits/DepositNoticePage.test.jsx
+++ b/frontend/src/features/deposits/DepositNoticePage.test.jsx
@@ -147,7 +147,9 @@ describe('DepositNoticePage', () => {
   // UX-03 rule 4: a ฿0 deposit notice is meaningless and would still advance
   // the ticket's payment track — issuing it must be blocked even though
   // rules 1-3 (customer name, >=1 item, description+qty) are all satisfied.
-  it('blocks issue when the computed total is zero', async () => {
+  // A % outside a whole 1–100 gets its own message on the % field (it used to blame the unit
+  // price, or pass the gate at 150% and fail behind the confirm dialog).
+  it('blocks issue when the computed total is zero, or the % is outside 1–100, before the dialog', async () => {
     api.depositNotices.listByTicket.mockResolvedValue({
       depositNotices: [{
         ...validDraftDoc,
@@ -163,6 +165,20 @@ describe('DepositNoticePage', () => {
 
     expect(await screen.findByText(/ยอดเงินรวมต้องมากกว่า 0/)).not.toBeNull();
     expect(screen.queryByRole('dialog')).toBeNull();
+
+    fireEvent.change(document.getElementById('doc-item-0-qty'), { target: { value: '5' } });
+    fireEvent.change(screen.getByPlaceholderText('ราคา'), { target: { value: '100' } });
+    const percentInput = screen.getByLabelText('% มัดจำ');
+    for (const typed of ['0', '150']) {
+      fireEvent.change(percentInput, { target: { value: typed } });
+      fireEvent.click(screen.getByRole('button', { name: /ออกเอกสาร/ }));
+      const error = await screen.findByText('กรุณากรอก % มัดจำเป็นจำนวนเต็ม 1–100');
+      expect(percentInput.getAttribute('aria-invalid')).toBe('true');
+      expect(percentInput.getAttribute('aria-describedby')).toBe(error.id);
+      expect(document.activeElement).toBe(percentInput);
+      expect(screen.queryByText(/ยอดเงินรวมต้องมากกว่า 0/)).toBeNull();
+      expect(screen.queryByRole('dialog')).toBeNull();
+    }
     expect(api.depositNotices.issue).not.toHaveBeenCalled();
   });
 
@@ -188,10 +204,115 @@ describe('DepositNoticePage', () => {
     expect(screen.queryByRole('alert')).toBeNull();
   });
 
+  // What บันทึก sends, and the summary beside it, must match what the backend stores:
+  // - a stored whole 0.33 shows, labels and saves as 33%;
+  // - a 100%-discounted line (net 0, unit 100) adds 0 and is sent at net 0, never its unit price;
+  // - money rounds per step like the backend: 100.10 at 33% is 33.03 + VAT 2.31 = 35.34 (35.35 unrounded);
+  // - a blank เพิ่มรายการ row is left out (the backend refuses a line without a description);
+  // - the draft's updatedAt travels as expectedUpdatedAt (a stale save is refused server-side);
+  // - a cleared % sends null, so the save keeps the stored % instead of failing the whole PUT.
+  it('saves what the backend will store: rounded %, zero-net line, per-step rounding, no blank row, the stamp, null for a cleared %', async () => {
+    api.depositNotices.listByTicket.mockResolvedValue({
+      depositNotices: [{
+        ...validDraftDoc, depositPercent: 0.33, updatedAt: '2026-10-23T08:57:19.732123Z',
+        items: [
+          { seq: 1, description: 'กระเบื้อง A', qty: 1, unit: 'แผ่น', unitPrice: 100.1, netUnitPrice: 100.1 },
+          { seq: 2, description: 'ของแถม', qty: 2, unit: 'แผ่น', unitPrice: 100, netUnitPrice: 0 },
+        ],
+      }],
+    });
+    renderDepositNoticePage();
+
+    await screen.findByText('รายการสินค้า (2 รายการ)');
+    const percentInput = screen.getByLabelText('% มัดจำ');
+    expect(percentInput.value).toBe('33');
+    expect(screen.getByText('ขอรับเงินมัดจำ (33%)')).not.toBeNull();
+    expect(screen.getByText('100.10 บาท')).not.toBeNull();
+    expect(screen.getByText('33.03 บาท')).not.toBeNull();
+    expect(screen.getByText('2.31 บาท')).not.toBeNull();
+    expect(screen.getByText('35.34 บาท')).not.toBeNull();
+
+    fireEvent.click(screen.getByRole('button', { name: /เพิ่มรายการ/ }));
+    fireEvent.click(screen.getByRole('button', { name: 'บันทึก' }));
+    await waitFor(() => expect(api.depositNotices.update).toHaveBeenCalledTimes(1));
+    const payload = api.depositNotices.update.mock.calls[0][1];
+    expect(payload).toMatchObject({ depositPercent: 0.33, expectedUpdatedAt: '2026-10-23T08:57:19.732123Z' });
+    expect(payload.items).toEqual([
+      expect.objectContaining({ seq: 1, unitPrice: 100.1, netUnitPrice: 100.1 }),
+      expect.objectContaining({ seq: 2, qty: 2, unitPrice: 100, netUnitPrice: 0 }),
+    ]);
+
+    fireEvent.change(percentInput, { target: { value: '' } });
+    fireEvent.click(screen.getByRole('button', { name: 'บันทึก' }));
+    await waitFor(() => expect(api.depositNotices.update).toHaveBeenCalledTimes(2));
+    expect(api.depositNotices.update.mock.calls[1][1].depositPercent).toBeNull();
+    expect(screen.queryByRole('alert')).toBeNull();
+  });
+
+  // The page must not rewrite what it did not edit: a stored 0.125 (shown as 13) survives a save of
+  // another field untouched.
+  it('keeps a stored non-whole % as-is when only another field is edited', async () => {
+    api.depositNotices.listByTicket.mockResolvedValue({
+      depositNotices: [{ ...validDraftDoc, depositPercent: 0.125, updatedAt: 'T1' }],
+    });
+    renderDepositNoticePage();
+
+    fireEvent.change(await screen.findByLabelText(/ที่อยู่/), { target: { value: 'ที่อยู่ใหม่' } });
+    fireEvent.click(screen.getByRole('button', { name: 'บันทึก' }));
+    await waitFor(() => expect(api.depositNotices.update).toHaveBeenCalledTimes(1));
+    expect(api.depositNotices.update.mock.calls[0][1]).toMatchObject({ depositPercent: 0.125, customerAddress: 'ที่อยู่ใหม่' });
+  });
+
+  // Blank rows are dropped from the payload and the backend keeps the stored lines when `items` is
+  // empty — so saving/previewing an all-blank form would "succeed" and bring the old lines back.
+  it('refuses to save or preview when every row was cleared, with the items error, and calls no API', async () => {
+    api.depositNotices.listByTicket.mockResolvedValue({ depositNotices: [validDraftDoc] });
+    renderDepositNoticePage();
+
+    await screen.findByDisplayValue('บริษัท ทดสอบ จำกัด');
+    fireEvent.change(document.getElementById('doc-item-0-description'), { target: { value: '' } });
+    fireEvent.change(document.getElementById('doc-item-0-qty'), { target: { value: '0' } });
+
+    fireEvent.click(screen.getByRole('button', { name: 'บันทึก' }));
+    expect((await screen.findByText('กรุณาเพิ่มรายการสินค้าอย่างน้อย 1 รายการ')).getAttribute('role')).toBe('alert');
+    expect(api.depositNotices.update).not.toHaveBeenCalled();
+
+    fireEvent.click(screen.getByRole('button', { name: /Preview|ตัวอย่าง/ }));
+    expect(api.depositNotices.update).not.toHaveBeenCalled();
+    expect(api.depositNotices.preview).not.toHaveBeenCalled();
+  });
+
+  // Someone else saved the draft since this page loaded it: the backend answers 409. The page
+  // reloads the draft (form and stamp) and shows the server's message, so the next save is a
+  // deliberate one over the fresh copy.
+  it('on a 409 save, reloads the draft and shows the server message', async () => {
+    const showToast = vi.fn();
+    api.depositNotices.listByTicket
+      .mockResolvedValueOnce({ depositNotices: [{ ...validDraftDoc, depositPercent: 0.3, updatedAt: 'T1' }] })
+      .mockResolvedValue({ depositNotices: [{ ...validDraftDoc, depositPercent: 0.4, updatedAt: 'T2' }] });
+    const stale = Object.assign(new Error('ใบแจ้งรับมัดจำนี้ถูกแก้ไขโดยผู้ใช้อื่น กรุณาโหลดข้อมูลใหม่แล้วลองอีกครั้ง'), { status: 409 });
+    api.depositNotices.update.mockRejectedValueOnce(stale);
+    renderDepositNoticePage({ showToast });
+
+    await screen.findByDisplayValue('บริษัท ทดสอบ จำกัด');
+    const percentInput = screen.getByLabelText('% มัดจำ');
+    fireEvent.change(percentInput, { target: { value: '35' } });
+    fireEvent.click(screen.getByRole('button', { name: 'บันทึก' }));
+
+    await waitFor(() => expect(showToast).toHaveBeenCalledWith('error', stale.message));
+    expect(api.depositNotices.update.mock.calls[0][1]).toMatchObject({ depositPercent: 0.35, expectedUpdatedAt: 'T1' });
+    await waitFor(() => expect(percentInput.value).toBe('40'));
+
+    fireEvent.click(screen.getByRole('button', { name: 'บันทึก' }));
+    await waitFor(() => expect(api.depositNotices.update).toHaveBeenCalledTimes(2));
+    expect(api.depositNotices.update.mock.calls[1][1]).toMatchObject({ depositPercent: 0.4, expectedUpdatedAt: 'T2' });
+  });
+
   // A fully valid document opens the confirm dialog, and confirming it calls
   // api.depositNotices.issue for that document.
-  it('opens the confirm dialog for a valid document and issues it on confirm', async () => {
-    api.depositNotices.listByTicket.mockResolvedValue({ depositNotices: [validDraftDoc] });
+  it('opens the confirm dialog for a valid document and issues it on confirm, with the stamp its own save returned', async () => {
+    api.depositNotices.listByTicket.mockResolvedValue({ depositNotices: [{ ...validDraftDoc, updatedAt: 'T1' }] });
+    api.depositNotices.update.mockResolvedValue({ depositNotice: { updatedAt: 'T2' } });
     renderDepositNoticePage();
 
     await screen.findByDisplayValue('บริษัท ทดสอบ จำกัด');
@@ -202,7 +323,7 @@ describe('DepositNoticePage', () => {
 
     fireEvent.click(within(dialog).getByRole('button', { name: 'ออกเอกสาร' }));
 
-    await waitFor(() => expect(api.depositNotices.issue).toHaveBeenCalledWith(9002));
+    await waitFor(() => expect(api.depositNotices.issue).toHaveBeenCalledWith(9002, { expectedUpdatedAt: 'T2' }));
   });
 
   it('renders the empty-state and lets the user create a draft', async () => {
@@ -214,8 +335,8 @@ describe('DepositNoticePage', () => {
     fireEvent.click(createButton);
 
     await waitFor(() => expect(api.depositNotices.createDraft).toHaveBeenCalledTimes(1));
-    // depositPercent is deliberately NOT sent (owner ruling, 2026-09-29): the backend always
-    // ignores a caller-supplied value now and re-sources it from the ticket's own quotation.
+    // depositPercent is not sent on create: the backend picks the draft's starting percent.
+    // Sales changes it on the draft afterwards.
     expect(api.depositNotices.createDraft).toHaveBeenCalledWith('701', {
       notes: ['หมายเหตุมาตรฐาน'],
     });
@@ -241,8 +362,7 @@ describe('DepositNoticePage', () => {
     fireEvent.click(createButton);
 
     await waitFor(() => expect(api.pricingRequests.createDepositNoticeFromQuotation).toHaveBeenCalledTimes(1));
-    // depositPercent is deliberately NOT sent (owner ruling, 2026-09-29) — the backend always
-    // ignores a caller-supplied value and re-sources it from the accepted quotation itself.
+    // depositPercent is not sent on create: the backend takes it from the accepted quotation.
     expect(api.pricingRequests.createDepositNoticeFromQuotation).toHaveBeenCalledWith(502, {});
     expect(api.depositNotices.createDraft).not.toHaveBeenCalled();
   });
@@ -297,24 +417,51 @@ describe('DepositNoticePage', () => {
     expect(await screen.findByDisplayValue('บริษัท ทดสอบ จำกัด')).not.toBeNull();
   });
 
-  // Owner ruling (2026-09-29): the deposit % is LOCKED to the source quotation and is no longer
-  // user-settable at the deposit-notice stage — the 30/50/70/100% preset buttons are gone, and
-  // the % renders as a plain read-only label sourced from the loaded draft's own depositPercent.
-  it('renders the deposit percent as a read-only label, with no preset buttons to change it', async () => {
+  // Owner ruling 2026-10-23: on a DRAFT the deposit % is an editable whole-number field (a typed
+  // 39.6 rounds to 40). The amount recalculates as sales types, and บันทึก sends the fraction.
+  // subtotal 500: 30% -> 150.00, 40% -> 200.00 deposit, 14.00 VAT, 214.00 total; cleared -> 0.
+  it('lets sales change the deposit percent on a draft, recalculates the amount, and saves it', async () => {
     api.depositNotices.listByTicket.mockResolvedValue({
       depositNotices: [{ ...validDraftDoc, depositPercent: 0.3 }],
     });
     renderDepositNoticePage();
 
     await screen.findByDisplayValue('บริษัท ทดสอบ จำกัด');
-
-    // No interactive control can change the percent anymore.
-    for (const label of ['30%', '50%', '70%', '100%']) {
-      expect(screen.queryByRole('button', { name: label })).toBeNull();
-    }
-    // The value the draft was loaded with (30%, not the 0.5 default) still renders, as a label.
-    expect(screen.getByText('30%')).not.toBeNull();
+    const percentInput = screen.getByLabelText('% มัดจำ');
+    expect(percentInput.disabled).toBe(false);
+    expect(percentInput.value).toBe('30');
     expect(screen.getByText('ขอรับเงินมัดจำ (30%)')).not.toBeNull();
+    expect(screen.getByText('150.00 บาท')).not.toBeNull();
+
+    fireEvent.change(percentInput, { target: { value: '39.6' } });
+
+    expect(percentInput.value).toBe('40');
+    expect(screen.getByText('ขอรับเงินมัดจำ (40%)')).not.toBeNull();
+    expect(screen.getByText('200.00 บาท')).not.toBeNull();
+    expect(screen.getByText('214.00 บาท')).not.toBeNull();
+    expect(screen.queryByText('150.00 บาท')).toBeNull();
+
+    fireEvent.click(screen.getByRole('button', { name: 'บันทึก' }));
+    await waitFor(() => expect(api.depositNotices.update).toHaveBeenCalledWith(
+      9002, expect.objectContaining({ depositPercent: 0.4 }),
+    ));
+
+    // A cleared field bills nothing: 0% and ฿0 for deposit, VAT and total, never a silent 50%.
+    fireEvent.change(percentInput, { target: { value: '' } });
+    expect(screen.getByText('ขอรับเงินมัดจำ (0%)')).not.toBeNull();
+    expect(screen.getAllByText('0.00 บาท')).toHaveLength(3);
+  });
+
+  it('shows the deposit percent read-only once the notice is issued', async () => {
+    api.depositNotices.listByTicket.mockResolvedValue({
+      depositNotices: [{ ...validDraftDoc, status: 'ISSUED', docNumber: 'GLRD69001', depositPercent: 0.3 }],
+    });
+    renderDepositNoticePage();
+
+    await screen.findByDisplayValue('บริษัท ทดสอบ จำกัด');
+    const percentInput = screen.getByLabelText('% มัดจำ');
+    expect(percentInput.disabled).toBe(true);
+    expect(percentInput.value).toBe('30');
   });
 
   // Issue #756: the VAT rate must come from the served document's vatPercent, not a
diff --git a/frontend/src/features/pricingRequests/PricingRequestDetailPage.jsx b/frontend/src/features/pricingRequests/PricingRequestDetailPage.jsx
index b08b0f1ff..ed27a51ba 100644
--- a/frontend/src/features/pricingRequests/PricingRequestDetailPage.jsx
+++ b/frontend/src/features/pricingRequests/PricingRequestDetailPage.jsx
@@ -36,6 +36,7 @@ import {
   canCreateCommercialOnlyRevision,
   canCreateCustomerQuotation,
   canCreateDepositNoticeFromQuotation,
+  issuedDepositNotice,
   canDecideDiscountApproval,
   canManageCustomerQuotation,
   canRecordCustomerQuotationOutcome,
@@ -1721,6 +1722,14 @@ export function PricingRequestDetailPage({ user, showToast }) {
     if (acceptConfirm) setAcceptToConfirm({ engine, quotation });
     else recordAccepted(engine, quotation);
   }
+  // Step 6: one deposit notice per deal (owner ruling 2026-10-23). Read only when the owner could
+  // otherwise be offered "สร้างใบแจ้งยอดเงินรับมัดจำ", so the block can point at an ISSUED one instead.
+  const depositNoticesQuery = useQuery({
+    queryKey: queryKeys.depositNotices(summary?.ticketId),
+    queryFn: () => api.depositNotices.listByTicket(summary.ticketId).then((r) => r.depositNotices ?? []),
+    enabled: summary != null && canCreateDepositNoticeFromQuotation(user, summary),
+  });
+  const issuedNotice = issuedDepositNotice(depositNoticesQuery.data);
   // itemId -> the factoryId Import has picked (as a string, matching SearchableCombobox's own
   // `code` convention) for that line. B6 (GLA-135): this used to hold the free-typed factory
   // NAME; it holds an id now, resolved server-side to the canonical master name on save. Same
@@ -4318,7 +4327,15 @@ export function PricingRequestDetailPage({ user, showToast }) {
                 </Button>
               </div>
             ) : null}
-            {canCreateDepositNoticeFromQuotation(user, summary, dealQuotationForPr) ? (
+            {issuedNotice && canCreateDepositNoticeFromQuotation(user, summary) ? (
+              <p className="text-sm text-text-muted">
+                ดีลนี้ออกใบแจ้งยอดเงินรับมัดจำแล้ว —{' '}
+                <Link to={`/tickets/${summary.ticketId}/deposit`} className="text-info underline">
+                  เปิดเลขที่ {issuedNotice.docNumber}
+                </Link>
+              </p>
+            ) : null}
+            {canCreateDepositNoticeFromQuotation(user, summary, dealQuotationForPr, depositNoticesQuery.data) ? (
               <div className="flex flex-col gap-2 rounded-md border border-border bg-surface p-3">
                 <p className="text-sm text-text-muted">
                   ยืนยันคำสั่งซื้อแล้ว — สร้างใบแจ้งยอดเงินรับมัดจำจากใบเสนอราคาที่ลูกค้ายอมรับ (แก้ไข/ออกเอกสารในหน้าใบแจ้งยอดเงินรับมัดจำ)
diff --git a/frontend/src/features/pricingRequests/PricingRequestDetailPage.test.jsx b/frontend/src/features/pricingRequests/PricingRequestDetailPage.test.jsx
index 5dee09c5e..e5ccc9d3c 100644
--- a/frontend/src/features/pricingRequests/PricingRequestDetailPage.test.jsx
+++ b/frontend/src/features/pricingRequests/PricingRequestDetailPage.test.jsx
@@ -75,6 +75,10 @@ vi.mock('../../api/index.js', () => ({
       confirmOrder: vi.fn(),
       createDepositNoticeFromQuotation: vi.fn(),
     },
+    // Step 6: the deal's deposit notices, so the create action is not offered once one is ISSUED.
+    depositNotices: {
+      listByTicket: vi.fn(),
+    },
     // CR-1 (GLA-167): lead-time change requests (R2 / R10).
     leadTimeChanges: {
       listForPricingRequest: vi.fn(),
@@ -328,6 +332,7 @@ function setApiDefaults() {
     result: { ticket: { summary: { id: 701 } }, pricingRequest: { id: 501, orderConfirmedAt: '2026-07-21T00:00:00Z' } },
   });
   api.pricingRequests.createDepositNoticeFromQuotation.mockResolvedValue({ depositNotice: { id: 9901, status: 'DRAFT' } });
+  api.depositNotices.listByTicket.mockResolvedValue({ depositNotices: [] });
   api.catalog.prices.mockResolvedValue({ items: [] });
   // B6 (GLA-135): a small real-looking factory roster — enough for the picker + duplicate-name
   // tests below without pulling in the full catalog fixture this file doesn't otherwise need.
@@ -3523,6 +3528,23 @@ describe('PricingRequestDetailPage Step 5: Customer Decision and Commercial Revi
 });
 
 describe('PricingRequestDetailPage Step 6: Deposit, Payment, and Order Confirmation', () => {
+  // Owner ruling 2026-10-23: one deposit notice per deal. Once one is ISSUED the create action is
+  // gone (the backend 409s it) and the block says which notice exists and where to open it.
+  it('replaces "สร้างใบแจ้งยอดเงินรับมัดจำ" with a pointer to the deal\'s ISSUED notice', async () => {
+    api.depositNotices.listByTicket.mockResolvedValue({
+      depositNotices: [{ id: 77, status: 'ISSUED', docNumber: 'GLRD69001', version: 1 }],
+    });
+    const request = buildRequest({ summary: { status: 'QUOTATION_ACCEPTED', orderConfirmedAt: '2026-07-21T00:00:00Z' } });
+    renderDetailPage({ user: salesOwner, request });
+    await waitForLoaded(request);
+
+    const link = await screen.findByRole('link', { name: /GLRD69001/ });
+    expect(link.getAttribute('href')).toBe(`/tickets/${request.summary.ticketId}/deposit`);
+    expect(screen.getByText(/ออกใบแจ้งยอดเงินรับมัดจำแล้ว/)).not.toBeNull();
+    expect(screen.queryByRole('button', { name: 'สร้างใบแจ้งยอดเงินรับมัดจำ' })).toBeNull();
+    expect(api.depositNotices.listByTicket).toHaveBeenCalledWith(request.summary.ticketId);
+  });
+
   it('offers "ยืนยันคำสั่งซื้อ" to the owning sales rep once QUOTATION_ACCEPTED, before the bridge has run', async () => {
     const request = buildRequest({ summary: { status: 'QUOTATION_ACCEPTED', orderConfirmedAt: null } });
     renderDetailPage({ user: salesOwner, request });
@@ -3568,6 +3590,23 @@ describe('PricingRequestDetailPage Step 6: Deposit, Payment, and Order Confirmat
     expect(screen.queryByRole('button', { name: 'สร้างใบแจ้งยอดเงินรับมัดจำ' })).toBeNull();
   });
 
+  // Owner ruling 2026-10-23: one deposit notice per deal. Once one is ISSUED the create action is
+  // gone (the backend 409s it) and the block says which notice exists and where to open it.
+  it('replaces "สร้างใบแจ้งยอดเงินรับมัดจำ" with a pointer to the deal\'s ISSUED notice', async () => {
+    api.depositNotices.listByTicket.mockResolvedValue({
+      depositNotices: [{ id: 77, status: 'ISSUED', docNumber: 'GLRD69001', version: 1 }],
+    });
+    const request = buildRequest({ summary: { status: 'QUOTATION_ACCEPTED', orderConfirmedAt: '2026-07-21T00:00:00Z' } });
+    renderDetailPage({ user: salesOwner, request });
+    await waitForLoaded(request);
+
+    const link = await screen.findByRole('link', { name: /GLRD69001/ });
+    expect(link.getAttribute('href')).toBe(`/tickets/${request.summary.ticketId}/deposit`);
+    expect(screen.getByText(/ออกใบแจ้งยอดเงินรับมัดจำแล้ว/)).not.toBeNull();
+    expect(screen.queryByRole('button', { name: 'สร้างใบแจ้งยอดเงินรับมัดจำ' })).toBeNull();
+    expect(api.depositNotices.listByTicket).toHaveBeenCalledWith(request.summary.ticketId);
+  });
+
   it('never shows either Step 6 button to CEO or Import — read-only', async () => {
     const request = buildRequest({ summary: { status: 'QUOTATION_ACCEPTED', orderConfirmedAt: null } });
     renderDetailPage({ user: ceoUser, request });
diff --git a/frontend/src/features/pricingRequests/pricingRequestMeta.js b/frontend/src/features/pricingRequests/pricingRequestMeta.js
index c176b2bbc..3d5810f92 100644
--- a/frontend/src/features/pricingRequests/pricingRequestMeta.js
+++ b/frontend/src/features/pricingRequests/pricingRequestMeta.js
@@ -308,10 +308,18 @@ export function confirmOrderBlockedReason(pr) {
  * only, reachable once the bridge action above has run (the endpoint's own precondition —
  * ticket.status=quotation_issued — is only true after confirmOrder). `acceptedQuotation` is the
  * page's new-engine quotation, when it has one: a ไม่รับมัดจำ (0%) one 409s on the server (#1173),
- * so it is not offered. The deal's deposit policy is not on the pricing-request payload. */
-export function canCreateDepositNoticeFromQuotation(user, pr, acceptedQuotation = null) {
+ * so it is not offered. The deal's deposit policy is not on the pricing-request payload. Never
+ * offered while the deal has an ISSUED deposit notice (one per deal,
+ * DepositNoticeService.createDraftFromQuotation). */
+export function canCreateDepositNoticeFromQuotation(user, pr, acceptedQuotation = null, depositNotices = []) {
   return canManageCustomerQuotation(user, pr) && pr?.status === 'QUOTATION_ACCEPTED' && Boolean(pr?.orderConfirmedAt)
-    && !(acceptedQuotation?.docStatus === 'ACCEPTED' && acceptedQuotation.depositPercent === 0);
+    && !(acceptedQuotation?.docStatus === 'ACCEPTED' && acceptedQuotation.depositPercent === 0)
+    && !issuedDepositNotice(depositNotices);
+}
+
+/** The deal's ISSUED deposit notice (at most one is live), or null. */
+export function issuedDepositNotice(depositNotices = []) {
+  return (depositNotices ?? []).find((d) => d.status === 'ISSUED') ?? null;
 }
 
 /** Mirrors PricingRequestService.cancel: owner sales OR ceo, any cancellable status. */
diff --git a/frontend/src/features/pricingRequests/pricingRequestMeta.test.js b/frontend/src/features/pricingRequests/pricingRequestMeta.test.js
index 49116ef43..18aa32b8c 100644
--- a/frontend/src/features/pricingRequests/pricingRequestMeta.test.js
+++ b/frontend/src/features/pricingRequests/pricingRequestMeta.test.js
@@ -452,6 +452,15 @@ describe('canCreateDepositNoticeFromQuotation', () => {
       { docStatus: 'ACCEPTED', depositPercent: null })).toBe(true);
     expect(canCreateDepositNoticeFromQuotation(salesOwner, confirmed, null)).toBe(true); // legacy chain
   });
+
+  // Owner ruling 2026-10-23 (DepositNoticeService.createDraftFromQuotation): one notice per deal.
+  it('rejects once the deal has an ISSUED deposit notice; a DRAFT or SUPERSEDED one does not block', () => {
+    const confirmed = pr({ status: 'QUOTATION_ACCEPTED', orderConfirmedAt: '2026-07-21T00:00:00Z' });
+    expect(canCreateDepositNoticeFromQuotation(salesOwner, confirmed, null,
+      [{ id: 1, status: 'SUPERSEDED' }, { id: 2, status: 'ISSUED', docNumber: 'GLRD69001' }])).toBe(false);
+    expect(canCreateDepositNoticeFromQuotation(salesOwner, confirmed, null,
+      [{ id: 1, status: 'SUPERSEDED' }, { id: 3, status: 'DRAFT' }])).toBe(true);
+  });
 });
 
 describe('canCancelPricingRequest', () => {
diff --git a/frontend/src/features/quotations/quotationMeta.js b/frontend/src/features/quotations/quotationMeta.js
index 236e78a19..66e1fa7a5 100644
--- a/frontend/src/features/quotations/quotationMeta.js
+++ b/frontend/src/features/quotations/quotationMeta.js
@@ -882,7 +882,7 @@ export function usesDirectNetPriceSqm(item, documentLanguage = 'TH') {
 // still always the SERVER's (see itemInputFromRow's own comment on that), and nothing here feeds
 // money math. They exist solely so the input can render/accept "แผ่น/ตร.ม." while the value that
 // actually travels to the server, and back, is still ตร.ม./แผ่น.
-function round2(n) {
+export function round2(n) {
   return Math.round((Number(n) + Number.EPSILON) * 100) / 100;
 }
 
diff --git a/frontend/src/features/tickets/DealDepositPanel.jsx b/frontend/src/features/tickets/DealDepositPanel.jsx
index 5356d5bae..3e5984594 100644
--- a/frontend/src/features/tickets/DealDepositPanel.jsx
+++ b/frontend/src/features/tickets/DealDepositPanel.jsx
@@ -4,12 +4,15 @@ import { Link, useNavigate } from 'react-router-dom';
 import { api, ROLE_PERMISSIONS } from '../../api/index.js';
 import { queryKeys } from '../../api/queryKeys.js';
 import { Button } from '../../components/common/Button.jsx';
+import { ConfirmDialog } from '../../components/common/ConfirmDialog.jsx';
 import { Panel } from '../../components/common/Layout.jsx';
 import { Modal } from '../../components/common/Modal.jsx';
 import { StatusBadge } from '../../components/common/StatusBadge.jsx';
 import { depositNoticeStatusLabel, depositPolicyLabel } from '../../utils/format.js';
 import { downloadBlob } from '../../utils/download.js';
 import { canCreateDepositNoticeFromQuotation } from '../pricingRequests/pricingRequestMeta.js';
+import { newestQuotationByRequest } from '../quotations/quotationMeta.js';
+import { DepositIssueSummary } from '../deposits/DepositNoticePage.jsx';
 import { buttonVariants } from '../../components/common/Button.jsx';
 import { cn } from '../../utils/cn.js';
 
@@ -86,7 +89,7 @@ function pickAcceptedPricingRequest(pricingRequests = []) {
  * its own "ยืนยันคำสั่งซื้อ..." box. Both panels can show that specific
  * create action at once until a notice exists for this deal.
  */
-export function DealDepositPanel({ user, ticketId, summary, availableActions = [], pricingRequests = [], showToast }) {
+export function DealDepositPanel({ user, ticketId, summary, availableActions = [], pricingRequests = [], dealQuotations = [], showToast }) {
   const queryClient = useQueryClient();
   const navigate = useNavigate();
   const role = user?.role;
@@ -100,6 +103,7 @@ export function DealDepositPanel({ user, ticketId, summary, availableActions = [
   const [policyReason, setPolicyReason] = useState('');
   const [downloadingFormat, setDownloadingFormat] = useState(null);
   const [previewHtml, setPreviewHtml] = useState('');
+  const [confirmIssue, setConfirmIssue] = useState(false);
 
   const st = summary?.status;
   const ps = summary?.paymentStatus;
@@ -157,13 +161,18 @@ export function DealDepositPanel({ user, ticketId, summary, availableActions = [
   });
 
   const issueMutation = useMutation({
-    mutationFn: () => api.depositNotices.issue(doc.id),
+    // The dialog shows the amounts as listed; the stamp makes the server refuse if the draft moved on since.
+    mutationFn: () => api.depositNotices.issue(doc.id, { expectedUpdatedAt: doc.updatedAt ?? null }),
     onSuccess: (res) => {
       showToast?.('success', `ออกเอกสาร ${res.depositNotice.docNumber} แล้ว`);
       setPreviewHtml('');
+      setConfirmIssue(false);
       invalidateAfterDepositChange();
     },
-    onError: (err) => showToast?.('error', err.message || 'ออกเอกสารไม่สำเร็จ'),
+    onError: (err) => {
+      setConfirmIssue(false);
+      showToast?.('error', err.message || 'ออกเอกสารไม่สำเร็จ');
+    },
   });
 
   const previewMutation = useMutation({
@@ -207,7 +216,7 @@ export function DealDepositPanel({ user, ticketId, summary, availableActions = [
   // Rule 4's cutoff), but the role/ownership check is kept here too, defense-in-depth, so this
   // control can never render editable off a stale/misconfigured availableActions response.
   const canSetPolicy = hasAction('WAIVE_DEPOSIT') && (role === 'sales_manager' || (isSales && isOwner));
-  const canCreateNotice = pr != null && canCreateDepositNoticeFromQuotation(user, pr);
+  const canCreateNotice = pr != null && canCreateDepositNoticeFromQuotation(user, pr, newestQuotationByRequest(dealQuotations).get(pr.id) ?? null, depositNoticesQuery.data);
   const canManageThisNotice = isSales && isOwner;
   // Legacy dual-track creation path (ticket.confirmCustomer → ISSUE_DEPOSIT_NOTICE),
   // independent of the PricingRequest/CustomerQuotation chain above — mirrors the
@@ -298,11 +307,14 @@ export function DealDepositPanel({ user, ticketId, summary, availableActions = [
                   </>
                 ) : canManageThisNotice ? (
                   <Button type="button" variant="primary" disabled={issueMutation.isPending}
-                    onClick={() => issueMutation.mutate()} data-testid="deal-deposit-issue-notice">
+                    onClick={() => setConfirmIssue(true)} data-testid="deal-deposit-issue-notice">
                     ออกเอกสาร
                   </Button>
                 ) : null}
               </div>
+              {doc.status === 'ISSUED' ? (
+                <p className="text-xs text-text-muted">ดีลนี้ออกใบแจ้งยอดเงินรับมัดจำแล้ว — สร้างฉบับใหม่ไม่ได้</p>
+              ) : null}
               {previewHtml ? (
                 <div className="flex flex-col gap-1">
                   <div className="flex items-center justify-between">
@@ -317,6 +329,9 @@ export function DealDepositPanel({ user, ticketId, summary, availableActions = [
           ) : canCreateNotice ? (
             <div className="flex flex-col gap-2">
               <p className="text-xs text-text-muted">ลูกค้ายืนยันคำสั่งซื้อแล้ว — สร้างใบแจ้งยอดเงินรับมัดจำจากใบเสนอราคาที่ยอมรับได้เลย</p>
+              {/* The backend picks a new notice's % and ignores a client value
+                  (DepositNoticeService.createDraftFromQuotation; findGoverningQuotation, #1170), so no
+                  % input here. Sales changes the % on the draft (DepositNoticePage, ruling 2026-10-23). */}
               <Button type="button" variant="primary" className="self-start" disabled={createNoticeMutation.isPending}
                 onClick={() => createNoticeMutation.mutate()} data-testid="deal-deposit-create-notice">
                 สร้างใบแจ้งยอดเงินรับมัดจำ
@@ -367,6 +382,21 @@ export function DealDepositPanel({ user, ticketId, summary, availableActions = [
         </div>
       </div>
 
+      {doc ? (
+        <ConfirmDialog
+          open={confirmIssue}
+          title="ยืนยันการออกเอกสาร"
+          message={(
+            <DepositIssueSummary customerName={doc.customerName} depositPercent={doc.depositPercent}
+              deposit={doc.depositAmount} vatPercent={doc.vatPercent} vat={doc.vatAmount} total={doc.totalPayable} />
+          )}
+          confirmLabel="ออกเอกสาร"
+          busy={issueMutation.isPending}
+          onCancel={() => setConfirmIssue(false)}
+          onConfirm={() => issueMutation.mutate()}
+        />
+      ) : null}
+
       {policyOpen ? (
         <Modal
           title="นโยบายมัดจำ"
diff --git a/frontend/src/features/tickets/TicketDetailPage.jsx b/frontend/src/features/tickets/TicketDetailPage.jsx
index 4e1d847b0..00f6663ca 100644
--- a/frontend/src/features/tickets/TicketDetailPage.jsx
+++ b/frontend/src/features/tickets/TicketDetailPage.jsx
@@ -2598,6 +2598,7 @@ export function TicketDetailPage({ user, ticketId, onBack, showToast }) {
                 summary={summary}
                 availableActions={availableActions}
                 pricingRequests={pricingRequests}
+                dealQuotations={dealQuotationRows}
                 showToast={showToast}
               />
             ) : null}
diff --git a/frontend/src/features/tickets/TicketDetailPage.test.jsx b/frontend/src/features/tickets/TicketDetailPage.test.jsx
index aeddb49b3..ff8b39439 100644
--- a/frontend/src/features/tickets/TicketDetailPage.test.jsx
+++ b/frontend/src/features/tickets/TicketDetailPage.test.jsx
@@ -3162,6 +3162,72 @@ describe('TicketDetailPage', () => {
       expect(section.queryByRole('button', { name: 'ยืนยันรับมัดจำ' })).toBeNull();
     });
 
+    // Owner ruling 2026-10-23: ออกเอกสาร on the deal page goes through a confirm dialog with the
+    // stored percent and amounts (the notice is a numbered customer document from then on).
+    it('the owning rep issues a draft notice only through a confirm dialog showing its % and amounts', async () => {
+      api.depositNotices.listByTicket.mockResolvedValue({ depositNotices: [{
+        id: 9002, ticketId: 701, version: 1, status: 'DRAFT', docNumber: null, customerName: 'บริษัท ทดสอบ จำกัด',
+        depositPercent: 0.4, depositAmount: 200, vatPercent: 0.07, vatAmount: 14, totalPayable: 214, items: [],
+        updatedAt: '2026-10-23T08:57:19.732123Z',
+      }] });
+      api.depositNotices.issue.mockResolvedValue({ depositNotice: { id: 9002, status: 'ISSUED', docNumber: 'GLRD69001' } });
+
+      renderTicketDetailPage(salesOwnerUser);
+      const section = await depositSection();
+      fireEvent.click(await section.findByRole('button', { name: 'ออกเอกสาร' }));
+
+      const dialog = await screen.findByRole('dialog');
+      expect(within(dialog).getByText('ขอรับเงินมัดจำ (40%)')).not.toBeNull();
+      expect(within(dialog).getByText('200.00 บาท')).not.toBeNull();
+      expect(within(dialog).getByText('ภาษีมูลค่าเพิ่ม 7%')).not.toBeNull();
+      expect(within(dialog).getByText('14.00 บาท')).not.toBeNull();
+      expect(within(dialog).getByText('214.00 บาท')).not.toBeNull();
+      expect(api.depositNotices.issue).not.toHaveBeenCalled();
+
+      fireEvent.click(within(dialog).getByRole('button', { name: 'ออกเอกสาร' }));
+      // The amounts in the dialog are the draft as read at that stamp; an edit since is refused server-side.
+      await waitFor(() => expect(api.depositNotices.issue).toHaveBeenCalledWith(9002, { expectedUpdatedAt: '2026-10-23T08:57:19.732123Z' }));
+    });
+
+    // Owner ruling 2026-10-23: one deposit notice per deal. With one ISSUED the panel never offers
+    // to create another (the backend 409s it), and says so beside the issued number.
+    it('with an ISSUED notice, offers no create action and says the deal already has its notice', async () => {
+      api.pricingRequests.listForTicket.mockResolvedValue({ items: [
+        { id: 501, ticketId: 701, ticketCreatedById: 1, status: 'QUOTATION_ACCEPTED', orderConfirmedAt: '2026-07-21T00:00:00Z' },
+      ] });
+      api.depositNotices.listByTicket.mockResolvedValue({ depositNotices: [{
+        id: 9001, ticketId: 701, version: 1, status: 'ISSUED', docNumber: 'GLRD69001', depositPercent: 0.4,
+        depositAmount: 200, vatPercent: 0.07, vatAmount: 14, totalPayable: 214, items: [],
+      }] });
+
+      renderTicketDetailPage(salesOwnerUser);
+      const section = await depositSection();
+
+      expect(await section.findByText('GLRD69001')).not.toBeNull();
+      expect(section.getByText('ดีลนี้ออกใบแจ้งยอดเงินรับมัดจำแล้ว — สร้างฉบับใหม่ไม่ได้')).not.toBeNull();
+      expect(section.queryByRole('button', { name: 'สร้างใบแจ้งยอดเงินรับมัดจำ' })).toBeNull();
+    });
+
+    // A ไม่รับมัดจำ (0%) accepted quotation 409s on the server (#1173): the panel passes the deal's
+    // accepted quotation (3rd arg) and the notices (4th) — it used to put the notices in the 3rd slot.
+    it('offers the create action for an accepted quotation, but not when that quotation is 0%', async () => {
+      api.pricingRequests.listForTicket.mockResolvedValue({ items: [
+        { id: 501, ticketId: 701, ticketCreatedById: 1, status: 'QUOTATION_ACCEPTED', orderConfirmedAt: '2026-07-21T00:00:00Z' },
+      ] });
+      const quotation = (depositPercent) => ({ id: 31, origin: 'PRICING_REQUEST', pricingRequestId: 501, docStatus: 'ACCEPTED', depositPercent });
+      api.dealQuotations.listForTicket.mockResolvedValue({ items: [quotation(0)] });
+      const { unmount } = renderTicketDetailPage(salesOwnerUser);
+      const section = await depositSection();
+      await waitFor(() => expect(api.dealQuotations.listForTicket).toHaveBeenCalled());
+      expect(section.queryByRole('button', { name: 'สร้างใบแจ้งยอดเงินรับมัดจำ' })).toBeNull();
+      unmount();
+
+      api.dealQuotations.listForTicket.mockResolvedValue({ items: [quotation(0.3)] });
+      renderTicketDetailPage(salesOwnerUser);
+      const section2 = await depositSection();
+      expect(await section2.findByRole('button', { name: 'สร้างใบแจ้งยอดเงินรับมัดจำ' })).not.toBeNull();
+    });
+
     it('import (no business in the deposit section) never gets a "การเงิน" tab at all', async () => {
       renderTicketDetailPage({ id: 7, employeeId: 7, name: 'ฝ่ายนำเข้า', role: 'import' });