diff --git a/src/controllers/customer-controller.ts b/src/controllers/customer-controller.ts
index 6b1d207..29571cc 100644
--- a/src/controllers/customer-controller.ts
+++ b/src/controllers/customer-controller.ts
@@ -441,7 +441,7 @@ export class CustomerController extends Controller {
 
     if (
       customerBranch &&
-      relation.find((a) => !customerBranch.find((b) => a.id !== b.id && a.branchNo === b.branchNo))
+      relation.find((a) => customerBranch.find((b) => a.id !== b.id && a.branchNo === b.branchNo))
     ) {
       throw new HttpError(
         HttpStatus.BAD_REQUEST,