diff --git a/handlers/business_updates.py b/handlers/business_updates.py
index 4a5f8ee..7ff4092 100644
--- a/handlers/business_updates.py
+++ b/handlers/business_updates.py
@@ -268,8 +268,6 @@ def _notify_incoming(bcid: str, customer_chat_id: int, text: str) -> None:
 # =============================================================================
 def on_edited_business_message(message) -> None:
     # Informational only: do NOT generate a new reply (prevents edit loops).
-    if not database.get_bool("monitoring_mode"):
-        return
     bcid = getattr(message, "business_connection_id", None)
     if not bcid:
         return
@@ -278,11 +276,24 @@ def on_edited_business_message(message) -> None:
     sender = getattr(message, "from_user", None)
     if sender and owner_user_id and sender.id == owner_user_id:
         return  # owner edited their own message
+    invalidated = database.invalidate_approvals_for_messages(
+        bcid, message.chat.id, [message.message_id]
+    )
+    log.info(
+        "customer edited message chat=%s (invalidated %d approvals)",
+        utils.mask_id(message.chat.id), invalidated,
+    )
+    if not database.get_bool("monitoring_mode"):
+        return
     name = business_service.customer_display_name(bcid, message.chat.id)
     text = (getattr(message, "text", None) or getattr(message, "caption", None) or "").strip()
+    cancellation = (
+        "\nThe pending approval for the earlier version was cancelled."
+        if invalidated else ""
+    )
     handlers.notify_owner(
         f"✏️ <b>{utils.escape(name)}</b> edited a message: "
-        f"<i>{utils.escape(text[:300])}</i>"
+        f"<i>{utils.escape(text[:300])}</i>{cancellation}"
     )
 
 
diff --git a/tests/unit/handlers/test_business_updates.py b/tests/unit/handlers/test_business_updates.py
index 8f35d0f..f1b53b2 100644
--- a/tests/unit/handlers/test_business_updates.py
+++ b/tests/unit/handlers/test_business_updates.py
@@ -196,7 +196,55 @@ def test_deliver_auto_warns_when_delivery_is_unconfirmed(
     assert db.get_recent_memory("bc1", 5, 10) == []
 
 
-# --- deleted messages --------------------------------------------------------
+# --- edited / deleted messages ----------------------------------------------
+def test_edited_customer_message_invalidates_approval(penv, make_message, mocker):
+    aid = penv.db.insert_pending_approval("bc1", 5, 22, "before", "reply")
+    notify = mocker.patch("handlers.notify_owner")
+
+    bu.on_edited_business_message(
+        make_message(
+            business_connection_id="bc1", chat_id=5, message_id=22, text="after"
+        )
+    )
+
+    assert penv.db.get_approval(aid)["status"] == "invalidated"
+    assert "pending approval for the earlier version was cancelled" in notify.call_args.args[0]
+
+
+def test_edited_customer_message_invalidates_with_monitoring_off(
+    penv, make_message, mocker
+):
+    penv.db.set_setting("monitoring_mode", False)
+    aid = penv.db.insert_pending_approval("bc1", 5, 22, "before", "reply")
+    notify = mocker.patch("handlers.notify_owner")
+
+    bu.on_edited_business_message(
+        make_message(
+            business_connection_id="bc1", chat_id=5, message_id=22, text="after"
+        )
+    )
+
+    assert penv.db.get_approval(aid)["status"] == "invalidated"
+    notify.assert_not_called()
+
+
+def test_edited_owner_message_does_not_invalidate_customer_approval(
+    penv, make_message, mocker
+):
+    aid = penv.db.insert_pending_approval("bc1", 5, 22, "customer", "reply")
+    notify = mocker.patch("handlers.notify_owner")
+
+    bu.on_edited_business_message(
+        make_message(
+            business_connection_id="bc1", user_id=999, chat_id=5,
+            message_id=22, text="owner edit",
+        )
+    )
+
+    assert penv.db.get_approval(aid)["status"] == "pending"
+    notify.assert_not_called()
+
+
 def test_deleted_invalidates_approval(penv):
     aid = penv.db.insert_pending_approval("bc1", 5, 22, "c", "r")
     deleted = SimpleNamespace(business_connection_id="bc1",