diff --git a/app/service/rest.py b/app/service/rest.py
index de0dff3b4..3122484f6 100644
--- a/app/service/rest.py
+++ b/app/service/rest.py
@@ -634,10 +634,13 @@ def add_service_sms_sender(service_id):
     dao_fetch_service_by_id(service_id)
     form = validate(request.get_json(), add_service_sms_sender_request)
     inbound_number_id = form.get('inbound_number_id', None)
+    sms_sender = form.get('sms_sender')
     if inbound_number_id:
-        dao_allocate_number_for_service(service_id=service_id, inbound_number_id=inbound_number_id)
+        updated_number = dao_allocate_number_for_service(service_id=service_id, inbound_number_id=inbound_number_id)
+        # the sms_sender in the form is the inbound_number_id from client, use number from table.
+        sms_sender = updated_number.number
     new_sms_sender = dao_add_sms_sender_for_service(service_id=service_id,
-                                                    sms_sender=form['sms_sender'],
+                                                    sms_sender=sms_sender,
                                                     is_default=form['is_default'],
                                                     inbound_number_id=inbound_number_id
                                                     )
diff --git a/tests/app/service/test_rest.py b/tests/app/service/test_rest.py
index 406f1a457..7db38221a 100644
--- a/tests/app/service/test_rest.py
+++ b/tests/app/service/test_rest.py
@@ -2595,7 +2595,7 @@ def test_add_service_sms_sender_when_it_is_an_inbound_number(client, notify_db_s
     service = create_service()
     inbound_number = create_inbound_number(number='12345')
     data = {
-        "sms_sender": inbound_number.number,
+        "sms_sender": str(inbound_number.id),
         "is_default": False,
         "inbound_number_id": str(inbound_number.id)
     }