diff --git a/src/controllers/customer-controller.ts b/src/controllers/customer-controller.ts
index 06e2f20..ca10da2 100644
--- a/src/controllers/customer-controller.ts
+++ b/src/controllers/customer-controller.ts
@@ -296,13 +296,16 @@ export class CustomerController extends Controller {
         "relationSubDistrictNotFound",
       );
     }
-    if (body.registeredBranchId && !branch) {
+    if (!!body.registeredBranchId && !branch) {
       throw new HttpError(
         HttpStatus.BAD_REQUEST,
         "Branch cannot be found.",
         "relationBranchNotFound",
       );
     }
+    if (!body.registeredBranchId) {
+      body.registeredBranchId = undefined;
+    }
 
     const record = await prisma.$transaction(
       async (tx) => {