diff --git a/src/components/01_branch-management/FormBranchInformation.vue b/src/components/01_branch-management/FormBranchInformation.vue
index 51172e49..80903a0c 100644
--- a/src/components/01_branch-management/FormBranchInformation.vue
+++ b/src/components/01_branch-management/FormBranchInformation.vue
@@ -60,7 +60,9 @@ defineProps<{
       v-model="taxNo"
       lazy-rules
       :rules="[
-        (val) => (val && val.length > 0) || $t('formDialogInputTaxNoValidate'),
+        (val) =>
+          (val && val.length === 13 && /[0-9]+/.test(val)) ||
+          $t('formDialogInputTaxNoValidate'),
       ]"
       for="input-tax-no"
     />