diff --git a/backend/app/schemas/tenant.py b/backend/app/schemas/tenant.py
index 7f5b15e..9dbf90b 100644
--- a/backend/app/schemas/tenant.py
+++ b/backend/app/schemas/tenant.py
@@ -5,7 +5,7 @@ from pydantic import BaseModel, EmailStr
 
 class TenantBase(BaseModel):
     code: str
-    prefix: str = ""
+    prefix: str
     name: str
     name_eng: Optional[str] = None
     tax_id: Optional[str] = None
diff --git a/frontend/admin-portal/tenants.html b/frontend/admin-portal/tenants.html
index 7747cdf..1d835a1 100644
--- a/frontend/admin-portal/tenants.html
+++ b/frontend/admin-portal/tenants.html
@@ -272,12 +272,20 @@ function editRow(t) {
 
 async function saveForm() {
   const id = document.getElementById('f-id').value;
+  const code = document.getElementById('f-code').value.trim();
+  const prefix = document.getElementById('f-prefix').value.trim();
+  const name = document.getElementById('f-name').value.trim();
+  const domain = document.getElementById('f-domain').value.trim();
+  if (!code || !prefix || !name || !domain) {
+    toast('代碼、前置碼、名稱、網域為必填', 'error');
+    return;
+  }
   const payload = {
-    code: document.getElementById('f-code').value.trim(),
-    prefix: document.getElementById('f-prefix').value.trim(),
-    name: document.getElementById('f-name').value.trim(),
+    code,
+    prefix,
+    name,
     name_eng: document.getElementById('f-name-eng').value.trim() || null,
-    domain: document.getElementById('f-domain').value.trim(),
+    domain,
     tax_id: document.getElementById('f-tax-id').value.trim() || null,
     quota_per_user: parseInt(document.getElementById('f-quota-user').value),
     total_quota: parseInt(document.getElementById('f-quota-total').value),