diff --git a/src/app/api/v1/orders/backfill-duplicate-checks/route.ts b/src/app/api/v1/orders/backfill-duplicate-checks/route.ts
index ec32e9d..b41bcc0 100644
--- a/src/app/api/v1/orders/backfill-duplicate-checks/route.ts
+++ b/src/app/api/v1/orders/backfill-duplicate-checks/route.ts
@@ -7,6 +7,12 @@
  * on new order creation (see orders-service.ts createOrder) — this
  * endpoint is what gets historical orders flagged too.
  *
+ * PREREQUISITE: The 7 PB admin fields documented in the per-matcher
+ * service files (order-number-duplicate-link-service.ts,
+ * order-order-duplicate-link-service.ts, order-delivery-note-link-service.ts)
+ * must exist on the `orders` collection before this endpoint can write
+ * to them. Without the fields, per-order updates will 500.
+ *
  * Intentionally sequential per order (not Promise.all) — this can run
  * over the full orders table, and PocketBase's admin client doesn't
  * love thousands of concurrent requests. This is a background/admin
diff --git a/src/lib/server/order-order-duplicate-link-service.test.ts b/src/lib/server/order-order-duplicate-link-service.test.ts
index 95b2dcf..41629c2 100644
--- a/src/lib/server/order-order-duplicate-link-service.test.ts
+++ b/src/lib/server/order-order-duplicate-link-service.test.ts
@@ -329,4 +329,18 @@ describe("suggestOrderDuplicate", () => {
     expect(updated.duplicate_order_match_confidence).toBe(1);
     expect(updated.potential_duplicate_order).toBe("order-edge-in");
   });
+
+  it("does not stamp _matching_attempted when order has no company (early return)", async () => {
+    const order = await pbMock.collection("orders").create({
+      id: "order-no-company",
+      // company deliberately omitted
+    });
+
+    const result = await suggestOrderDuplicate(order.id);
+
+    expect(result.duplicateOrderId).toBeNull();
+    expect(result.method).toBe("no_match");
+    const updated = await pbMock.collection("orders").getOne("order-no-company");
+    expect(updated.duplicate_order_matching_attempted).toBeFalsy();
+  });
 });