diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0aba1ec..861aa7f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,9 +7,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Unreleased
 
-### Updated
+### Fixed
 
-Document newly required `key` value for `tiles` when creating and updating reports via `dx studio reports`.
+- `dx studio reports init --id`: The scaffolded YAML now includes each tile's `id`, so `dx studio reports update` preserves existing tiles (including their sizing) instead of re-creating them. `dx studio reports create` continues to strip tile IDs, since a new report always gets fresh tiles.
 
 ## 0.5.3 - 2026-06-26
 
diff --git a/src/commands/studio/reports.test.ts b/src/commands/studio/reports.test.ts
index b71858e..071dcbb 100644
--- a/src/commands/studio/reports.test.ts
+++ b/src/commands/studio/reports.test.ts
@@ -2,6 +2,7 @@ import { EventEmitter } from "events";
 import fs from "fs";
 
 import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import { parse as parseYaml } from "yaml";
 
 import { EXIT_CODES } from "../../errors.js";
 
@@ -240,6 +241,56 @@ describe("studio reports command", () => {
       expect(body.name).toBe("Web Metrics");
     });
 
+    it("--from-file strips tile ids before posting", async () => {
+      process.env.DX_API_BASE_URL = "https://api.example.com";
+      getToken.mockReturnValue("token-123");
+
+      const fetchMock = vi.fn().mockResolvedValueOnce(
+        new Response(JSON.stringify({ ok: true, report }), {
+          status: 200,
+        }),
+      );
+      vi.stubGlobal("fetch", fetchMock);
+
+      const { run } = await import("../../cli.js");
+      stubReadFileSyncForFixturePath(
+        "my-report.yaml",
+        [
+          "name: Web Metrics",
+          "owner_email: owner@example.com",
+          "tiles:",
+          "  - id: tile_from_source",
+          "    title: Median visit duration",
+          "    sql: SELECT 1",
+          "    chart_type: table",
+          "    chart_config: {}",
+          "",
+        ].join("\n"),
+      );
+
+      await run([
+        "node",
+        "dx",
+        "studio",
+        "reports",
+        "create",
+        "--from-file",
+        "./my-report.yaml",
+      ]);
+
+      const body = JSON.parse(
+        (fetchMock.mock.calls[0][1] as { body: string }).body,
+      );
+      expect(body.tiles).toEqual([
+        {
+          title: "Median visit duration",
+          sql: "SELECT 1",
+          chart_type: "table",
+          chart_config: {},
+        },
+      ]);
+    });
+
     it("--from-file returns JSON with --json flag", async () => {
       process.env.DX_API_BASE_URL = "https://api.example.com";
       getToken.mockReturnValue("token-123");
@@ -535,12 +586,53 @@ describe("studio reports command", () => {
       ]);
 
       const yaml = writeFileSyncSpy.mock.calls[0]?.[1] as string;
-      expect(yaml).not.toContain("id:");
+      // The report-level id is read-only and must not be written.
+      expect(yaml).not.toContain("id: rpt_new");
       expect(yaml).not.toContain("url:");
       expect(yaml).not.toContain("created_at:");
       expect(yaml).not.toContain("updated_at:");
-      expect(yaml).not.toContain("tile_line");
-      expect(yaml).not.toContain("tile_table");
+    });
+
+    it("--id scaffolds each tile with its id so updates preserve tiles", async () => {
+      process.env.DX_API_BASE_URL = "https://api.example.com";
+      getToken.mockReturnValue("token-123");
+
+      vi.stubGlobal(
+        "fetch",
+        vi.fn().mockResolvedValueOnce(
+          new Response(JSON.stringify(infoResponse), {
+            status: 200,
+          }),
+        ),
+      );
+      const writeFileSyncSpy = vi
+        .spyOn(fs, "writeFileSync")
+        .mockImplementation(() => undefined);
+
+      const { run } = await import("../../cli.js");
+      await run([
+        "node",
+        "dx",
+        "studio",
+        "reports",
+        "init",
+        "./my-report.yaml",
+        "--id",
+        "rpt_new",
+      ]);
+
+      const yaml = writeFileSyncSpy.mock.calls[0]?.[1] as string;
+      expect(yaml).toContain("id: tile_line");
+      expect(yaml).toContain("id: tile_table");
+
+      // The scaffolded YAML round-trips into an update payload that keeps IDs.
+      const parsed = parseYaml(yaml) as {
+        tiles: { id: string }[];
+      };
+      expect(parsed.tiles.map((tile) => tile.id)).toEqual([
+        "tile_line",
+        "tile_table",
+      ]);
     });
 
     it("--id returns JSON with --json flag", async () => {
diff --git a/src/commands/studio/reports.ts b/src/commands/studio/reports.ts
index 7dc5d78..85b8e2c 100644
--- a/src/commands/studio/reports.ts
+++ b/src/commands/studio/reports.ts
@@ -336,6 +336,7 @@ type StudioReport = {
 };
 
 type StudioReportTilePayload = {
+  id?: string;
   title: string | null;
   sql: string | null;
   chart_type: string;
@@ -586,8 +587,20 @@ async function readYamlStdin(): Promise<unknown> {
 }
 
 function buildCreateReportPayload(raw: unknown): CreateStudioReportPayload {
-  const { id: _id, ...rest } = parseYamlObject(raw);
-  return rest as CreateStudioReportPayload;
+  const { id: _id, tiles, ...rest } = parseYamlObject(raw);
+  const payload = rest as CreateStudioReportPayload;
+  if (Array.isArray(tiles)) {
+    // A new report always gets fresh tiles, so drop any tile IDs carried over
+    // from an `init --id` scaffold (those IDs belong to the source report).
+    payload.tiles = tiles.map((tile) => {
+      if (!tile || typeof tile !== "object") {
+        return tile as StudioReportTilePayload;
+      }
+      const { id: _tileId, ...tileRest } = tile as StudioReportTilePayload;
+      return tileRest as StudioReportTilePayload;
+    });
+  }
+  return payload;
 }
 
 function buildUpdateReportPayload(
@@ -624,6 +637,7 @@ function studioReportToYaml(report: StudioReport): string {
     edit_access_type: report.edit_access_type,
     editor_emails: [],
     tiles: report.tiles.map((tile) => ({
+      id: tile.id,
       title: tile.title,
       sql: tile.sql,
       chart_type: tile.chart_type,