diff --git a/src/controllers/customer-controller.ts b/src/controllers/customer-controller.ts
index 9509f37..6b1d207 100644
--- a/src/controllers/customer-controller.ts
+++ b/src/controllers/customer-controller.ts
@@ -49,6 +49,7 @@ export type CustomerCreate = {
 
     legalPersonNo: string;
 
+    branchNo: number;
     taxNo: string | null;
     name: string;
     nameEN: string;
@@ -95,6 +96,7 @@ export type CustomerUpdate = {
 
     legalPersonNo: string;
 
+    branchNo: number;
     taxNo: string | null;
     name: string;
     nameEN: string;
@@ -331,10 +333,9 @@ export class CustomerController extends Controller {
             branch: {
               createMany: {
                 data:
-                  customerBranch?.map((v, i) => ({
+                  customerBranch?.map((v) => ({
                     ...v,
-                    branchNo: i + 1,
-                    code: `${last.key.slice(9)}${last.value.toString().padStart(6, "0")}-${(i + 1).toString().padStart(2, "0")}`,
+                    code: `${last.key.slice(9)}${last.value.toString().padStart(6, "0")}-${v.branchNo.toString().padStart(2, "0")}`,
                     createdByUserId: req.user.sub,
                     updatedByUserId: req.user.sub,
                   })) || [],
@@ -438,6 +439,17 @@ export class CustomerController extends Controller {
       );
     }
 
+    if (
+      customerBranch &&
+      relation.find((a) => !customerBranch.find((b) => a.id !== b.id && a.branchNo === b.branchNo))
+    ) {
+      throw new HttpError(
+        HttpStatus.BAD_REQUEST,
+        "Branch cannot have same number.",
+        "oneOrMoreBranchNoExist",
+      );
+    }
+
     const record = await prisma.customer
       .update({
         include: {
@@ -463,20 +475,19 @@ export class CustomerController extends Controller {
                 },
                 status: Status.CREATED,
               },
-              upsert: customerBranch.map((v, i) => ({
+              upsert: customerBranch.map((v) => ({
                 where: { id: v.id || "" },
                 create: {
                   ...v,
-                  branchNo: i + 1,
-                  code: `${customer.code}-${(i + 1).toString().padStart(2, "0")}`,
+                  code: `${customer.code}-${v.branchNo.toString().padStart(2, "0")}`,
                   createdByUserId: req.user.sub,
                   updatedByUserId: req.user.sub,
                   id: undefined,
                 },
                 update: {
                   ...v,
-                  branchNo: i + 1,
-                  code: `${customer.code}-${(i + 1).toString().padStart(2, "0")}`,
+                  code: undefined,
+                  branchNo: undefined,
                   updatedByUserId: req.user.sub,
                 },
               })),