diff --git a/backend/src/find_api/routers/upload.py b/backend/src/find_api/routers/upload.py
index 760f0ba2..5e875206 100644
--- a/backend/src/find_api/routers/upload.py
+++ b/backend/src/find_api/routers/upload.py
@@ -40,6 +40,12 @@ async def upload_images(
     Returns:
         List of created media records with job IDs
     """
+    if len(files) > settings.MAX_BULK_FILES:
+        raise HTTPException(
+            413,
+            f"Request contains more than {settings.MAX_BULK_FILES} files",
+        )
+
     results = []
 
     for file in files:
diff --git a/backend/tests/test_upload.py b/backend/tests/test_upload.py
index 741aa5fa..5e7d252f 100644
--- a/backend/tests/test_upload.py
+++ b/backend/tests/test_upload.py
@@ -114,6 +114,57 @@ def test_missing_files_returns_422(self, client):
         assert response.status_code == 422
 
 
+class TestMultipartUploadLimit:
+    """The multipart endpoint enforces MAX_BULK_FILES before ingestion."""
+
+    @staticmethod
+    def _files(count: int):
+        data = get_valid_image_bytes()
+        return [
+            ("files", (f"photo-{index}.png", data, "image/png"))
+            for index in range(count)
+        ]
+
+    def test_below_limit_proceeds(self, client):
+        with (
+            patch("find_api.routers.upload.settings.MAX_BULK_FILES", 3),
+            patch(
+                "find_api.routers.upload._ingest_image",
+                return_value={"status": "uploaded"},
+            ) as ingest,
+        ):
+            response = client.post("/api/upload", files=self._files(2))
+
+        assert response.status_code == 200
+        assert response.json()["total"] == 2
+        assert ingest.call_count == 2
+
+    def test_exact_limit_proceeds(self, client):
+        with (
+            patch("find_api.routers.upload.settings.MAX_BULK_FILES", 3),
+            patch(
+                "find_api.routers.upload._ingest_image",
+                return_value={"status": "uploaded"},
+            ) as ingest,
+        ):
+            response = client.post("/api/upload", files=self._files(3))
+
+        assert response.status_code == 200
+        assert response.json()["total"] == 3
+        assert ingest.call_count == 3
+
+    def test_above_limit_is_rejected_before_ingestion(self, client):
+        with (
+            patch("find_api.routers.upload.settings.MAX_BULK_FILES", 3),
+            patch("find_api.routers.upload._ingest_image") as ingest,
+        ):
+            response = client.post("/api/upload", files=self._files(4))
+
+        assert response.status_code == 413
+        assert response.json()["detail"] == "Request contains more than 3 files"
+        ingest.assert_not_called()
+
+
 class TestBulkUpload:
     """Bulk ZIP upload behavior."""