diff --git a/app/schemas.py b/app/schemas.py
index 3a0ab41df..050e35d48 100644
--- a/app/schemas.py
+++ b/app/schemas.py
@@ -1,4 +1,5 @@
 import re
+from flask import current_app
 from flask_marshmallow.fields import fields
 from . import ma
 from . import models
@@ -102,12 +103,15 @@ class SmsTemplateNotificationSchema(SmsNotificationSchema):
     @validates_schema
     def validate_schema(self, data):
         """
-        Validate the to field is valid for this template
+        Validate the to field is valid for this notification
         """
+        from app import api_user
         template_id = data.get('template', None)
         template = models.Template.query.filter_by(id=template_id).first()
         if template:
             service = template.service
+            # Validate restricted service,
+            # restricted services can only send to one of its users.
             if service.restricted:
                 valid = False
                 for usr in service.users:
@@ -116,6 +120,11 @@ class SmsTemplateNotificationSchema(SmsNotificationSchema):
                         break
                 if not valid:
                     raise ValidationError('Invalid phone number for restricted service', 'restricted')
+            # Assert the template is valid for the service which made the request.
+            service = api_user['client']
+            if (service != current_app.config.get('ADMIN_CLIENT_USER_NAME') and
+               template.service != models.Service.query.filter_by(id=service).first()):
+                raise ValidationError('Invalid template', 'restricted')
 
 
 class SmsAdminNotificationSchema(SmsNotificationSchema):
diff --git a/tests/app/notifications/test_rest.py b/tests/app/notifications/test_rest.py
index d3c2170e8..33cef53b0 100644
--- a/tests/app/notifications/test_rest.py
+++ b/tests/app/notifications/test_rest.py
@@ -4,6 +4,8 @@ import uuid
 from tests import create_authorization_header
 from flask import url_for, json
 from app.models import Service
+from tests.app.conftest import sample_service as create_sample_service
+from tests.app.conftest import sample_template as create_sample_template
 
 
 def test_get_notifications(
@@ -172,6 +174,38 @@ def test_send_notification_invalid_template_id(notify_api,
             assert 'Template not found' in json_resp['message']['template']
 
 
+@moto.mock_sqs
+def test_should_not_allow_template_from_other_service(notify_api,
+                                                      notify_db,
+                                                      notify_db_session,
+                                                      sample_template,
+                                                      sample_admin_service_id,
+                                                      mocker):
+    """
+    Tests POST endpoint '/sms' with notifications.
+    """
+    with notify_api.test_request_context():
+        with notify_api.test_client() as client:
+            data = {
+                'to': '+441234123123',
+                'template': sample_template.id
+            }
+            auth_header = create_authorization_header(
+                service_id=sample_admin_service_id,
+                request_body=json.dumps(data),
+                path=url_for('notifications.create_sms_notification'),
+                method='POST')
+
+            response = client.post(
+                url_for('notifications.create_sms_notification'),
+                data=json.dumps(data),
+                headers=[('Content-Type', 'application/json'), auth_header])
+
+            json_resp = json.loads(response.get_data(as_text=True))
+            assert response.status_code == 400
+            assert 'Invalid template' in json_resp['message']['restricted']
+
+
 @moto.mock_sqs
 def test_should_allow_valid_message(notify_api,
                                     notify_db,