diff --git a/sdk/eventgrid/azure-eventgrid/azure/eventgrid/_operations/_patch.py b/sdk/eventgrid/azure-eventgrid/azure/eventgrid/_operations/_patch.py
index 7f838894136c..0606157136ab 100644
--- a/sdk/eventgrid/azure-eventgrid/azure/eventgrid/_operations/_patch.py
+++ b/sdk/eventgrid/azure-eventgrid/azure/eventgrid/_operations/_patch.py
@@ -135,8 +135,8 @@ def _http_response_error_handler(self, exception):
             if exception.status_code == 404:
                 raise ResourceNotFoundError(
                     "Resource not found. "
-                    "Please check that the tier you are using, corresponds to the correct "
-                    "endpoint and/or topic name."
+                    "For Event Grid Namespaces, please specify the namespace_topic name on the client. "
+                     "For Event Grid Basic, do not specify the namespace_topic name."
                 ) from exception
             raise exception
 
diff --git a/sdk/eventgrid/azure-eventgrid/azure/eventgrid/aio/_operations/_patch.py b/sdk/eventgrid/azure-eventgrid/azure/eventgrid/aio/_operations/_patch.py
index d5fefd748437..4cd5f859561d 100644
--- a/sdk/eventgrid/azure-eventgrid/azure/eventgrid/aio/_operations/_patch.py
+++ b/sdk/eventgrid/azure-eventgrid/azure/eventgrid/aio/_operations/_patch.py
@@ -119,8 +119,8 @@ def _http_response_error_handler(self, exception):
             if exception.status_code == 404:
                 raise ResourceNotFoundError(
                     "Resource not found. "
-                    "Please check that the tier you are using, corresponds to the correct "
-                    "endpoint and/or topic name."
+                    "For Event Grid Namespaces, please specify the namespace_topic name on the client. "
+                    "For Event Grid Basic, do not specify the namespace_topic name."
                 ) from exception
             raise exception
 
diff --git a/sdk/eventgrid/azure-eventgrid/tests/test_eg_consumer_client.py b/sdk/eventgrid/azure-eventgrid/tests/test_eg_consumer_client.py
index b04175ed32fc..07798d0b8b35 100644
--- a/sdk/eventgrid/azure-eventgrid/tests/test_eg_consumer_client.py
+++ b/sdk/eventgrid/azure-eventgrid/tests/test_eg_consumer_client.py
@@ -48,15 +48,8 @@ def test_receive_data(self, **kwargs):
         eventgrid_key = kwargs["eventgrid_key"]
         eventgrid_topic_name = kwargs["eventgrid_topic_name"]
         eventgrid_event_subscription_name = kwargs["eventgrid_event_subscription_name"]
-        publisher = EventGridPublisherClient(
-            eventgrid_endpoint, AzureKeyCredential(eventgrid_key), namespace_topic=eventgrid_topic_name
-        )
-        consumer = EventGridConsumerClient(
-            eventgrid_endpoint,
-            AzureKeyCredential(eventgrid_key),
-            namespace_topic=eventgrid_topic_name,
-            subscription=eventgrid_event_subscription_name,
-        )
+        publisher = self.create_eg_publisher_client(eventgrid_endpoint, eventgrid_topic_name)
+        consumer = self.create_eg_consumer_client(eventgrid_endpoint, eventgrid_topic_name, eventgrid_event_subscription_name)
         cloud_event = CloudEvent(
             source="http://samplesource.dev",
             data={"sample": "cloudevent"},
@@ -78,15 +71,9 @@ def test_receive_renew_data(self, **kwargs):
         eventgrid_key = kwargs["eventgrid_key"]
         eventgrid_topic_name = kwargs["eventgrid_topic_name"]
         eventgrid_event_subscription_name = kwargs["eventgrid_event_subscription_name"]
-        publisher = EventGridPublisherClient(
-            eventgrid_endpoint, AzureKeyCredential(eventgrid_key), namespace_topic=eventgrid_topic_name
-        )
-        consumer = EventGridConsumerClient(
-            eventgrid_endpoint,
-            AzureKeyCredential(eventgrid_key),
-            namespace_topic=eventgrid_topic_name,
-            subscription=eventgrid_event_subscription_name,
-        )
+        publisher = self.create_eg_publisher_client(eventgrid_endpoint, eventgrid_topic_name)
+        consumer = self.create_eg_consumer_client(eventgrid_endpoint, eventgrid_topic_name, eventgrid_event_subscription_name)
+
         cloud_event = CloudEvent(
             source="http://samplesource.dev",
             data={"sample": "cloudevent"},
@@ -109,15 +96,9 @@ def test_receive_release_data(self, **kwargs):
         eventgrid_key = kwargs["eventgrid_key"]
         eventgrid_topic_name = kwargs["eventgrid_topic_name"]
         eventgrid_event_subscription_name = kwargs["eventgrid_event_subscription_name"]
-        publisher = EventGridPublisherClient(
-            eventgrid_endpoint, AzureKeyCredential(eventgrid_key), namespace_topic=eventgrid_topic_name
-        )
-        consumer = EventGridConsumerClient(
-            eventgrid_endpoint,
-            AzureKeyCredential(eventgrid_key),
-            namespace_topic=eventgrid_topic_name,
-            subscription=eventgrid_event_subscription_name,
-        )
+        publisher = self.create_eg_publisher_client(eventgrid_endpoint, eventgrid_topic_name)
+        consumer = self.create_eg_consumer_client(eventgrid_endpoint, eventgrid_topic_name, eventgrid_event_subscription_name)
+
         cloud_event = CloudEvent(
             source="http://samplesource.dev",
             data={"sample": "cloudevent"},
@@ -139,15 +120,9 @@ def test_receive_reject_data(self, **kwargs):
         eventgrid_key = kwargs["eventgrid_key"]
         eventgrid_topic_name = kwargs["eventgrid_topic_name"]
         eventgrid_event_subscription_name = kwargs["eventgrid_event_subscription_name"]
-        publisher = EventGridPublisherClient(
-            eventgrid_endpoint, AzureKeyCredential(eventgrid_key), namespace_topic=eventgrid_topic_name
-        )
-        consumer = EventGridConsumerClient(
-            eventgrid_endpoint,
-            AzureKeyCredential(eventgrid_key),
-            namespace_topic=eventgrid_topic_name,
-            subscription=eventgrid_event_subscription_name,
-        )
+        publisher = self.create_eg_publisher_client(eventgrid_endpoint, eventgrid_topic_name)
+        consumer = self.create_eg_consumer_client(eventgrid_endpoint, eventgrid_topic_name, eventgrid_event_subscription_name)
+
         cloud_event = CloudEvent(
             source="http://samplesource.dev",
             data={"sample": "cloudevent"},
diff --git a/sdk/eventgrid/azure-eventgrid/tests/test_eg_consumer_client_async.py b/sdk/eventgrid/azure-eventgrid/tests/test_eg_consumer_client_async.py
index a73452700184..b3bd78a78fdd 100644
--- a/sdk/eventgrid/azure-eventgrid/tests/test_eg_consumer_client_async.py
+++ b/sdk/eventgrid/azure-eventgrid/tests/test_eg_consumer_client_async.py
@@ -50,15 +50,8 @@ async def test_receive_data(self, **kwargs):
         eventgrid_key = kwargs["eventgrid_key"]
         eventgrid_topic_name = kwargs["eventgrid_topic_name"]
         eventgrid_event_subscription_name = kwargs["eventgrid_event_subscription_name"]
-        publisher = EventGridPublisherClient(
-            eventgrid_endpoint, AzureKeyCredential(eventgrid_key), namespace_topic=eventgrid_topic_name
-        )
-        consumer = EventGridConsumerClient(
-            eventgrid_endpoint,
-            AzureKeyCredential(eventgrid_key),
-            namespace_topic=eventgrid_topic_name,
-            subscription=eventgrid_event_subscription_name,
-        )
+        publisher = self.create_eg_publisher_client(eventgrid_endpoint, eventgrid_topic_name)
+        consumer = self.create_eg_consumer_client(eventgrid_endpoint, eventgrid_topic_name, eventgrid_event_subscription_name)
         cloud_event = CloudEvent(
             source="http://samplesource.dev",
             data={"sample": "cloudevent"},
@@ -81,15 +74,8 @@ async def test_receive_renew_data(self, **kwargs):
         eventgrid_key = kwargs["eventgrid_key"]
         eventgrid_topic_name = kwargs["eventgrid_topic_name"]
         eventgrid_event_subscription_name = kwargs["eventgrid_event_subscription_name"]
-        publisher = EventGridPublisherClient(
-            eventgrid_endpoint, AzureKeyCredential(eventgrid_key), namespace_topic=eventgrid_topic_name
-        )
-        consumer = EventGridConsumerClient(
-            eventgrid_endpoint,
-            AzureKeyCredential(eventgrid_key),
-            namespace_topic=eventgrid_topic_name,
-            subscription=eventgrid_event_subscription_name,
-        )
+        publisher = self.create_eg_publisher_client(eventgrid_endpoint, eventgrid_topic_name)
+        consumer = self.create_eg_consumer_client(eventgrid_endpoint, eventgrid_topic_name, eventgrid_event_subscription_name)
         cloud_event = CloudEvent(
             source="http://samplesource.dev",
             data={"sample": "cloudevent"},
@@ -113,15 +99,8 @@ async def test_receive_release_data(self, **kwargs):
         eventgrid_key = kwargs["eventgrid_key"]
         eventgrid_topic_name = kwargs["eventgrid_topic_name"]
         eventgrid_event_subscription_name = kwargs["eventgrid_event_subscription_name"]
-        publisher = EventGridPublisherClient(
-            eventgrid_endpoint, AzureKeyCredential(eventgrid_key), namespace_topic=eventgrid_topic_name
-        )
-        consumer = EventGridConsumerClient(
-            eventgrid_endpoint,
-            AzureKeyCredential(eventgrid_key),
-            namespace_topic=eventgrid_topic_name,
-            subscription=eventgrid_event_subscription_name,
-        )
+        publisher = self.create_eg_publisher_client(eventgrid_endpoint, eventgrid_topic_name)
+        consumer = self.create_eg_consumer_client(eventgrid_endpoint, eventgrid_topic_name, eventgrid_event_subscription_name)
         cloud_event = CloudEvent(
             source="http://samplesource.dev",
             data={"sample": "cloudevent"},
@@ -144,15 +123,8 @@ async def test_receive_reject_data(self, **kwargs):
         eventgrid_key = kwargs["eventgrid_key"]
         eventgrid_topic_name = kwargs["eventgrid_topic_name"]
         eventgrid_event_subscription_name = kwargs["eventgrid_event_subscription_name"]
-        publisher = EventGridPublisherClient(
-            eventgrid_endpoint, AzureKeyCredential(eventgrid_key), namespace_topic=eventgrid_topic_name
-        )
-        consumer = EventGridConsumerClient(
-            eventgrid_endpoint,
-            AzureKeyCredential(eventgrid_key),
-            namespace_topic=eventgrid_topic_name,
-            subscription=eventgrid_event_subscription_name,
-        )
+        publisher = self.create_eg_publisher_client(eventgrid_endpoint, eventgrid_topic_name)
+        consumer = self.create_eg_consumer_client(eventgrid_endpoint, eventgrid_topic_name, eventgrid_event_subscription_name)
         cloud_event = CloudEvent(
             source="http://samplesource.dev",
             data={"sample": "cloudevent"},
diff --git a/sdk/eventgrid/azure-eventgrid/tests/test_eg_publisher_client.py b/sdk/eventgrid/azure-eventgrid/tests/test_eg_publisher_client.py
index 270e4c1d76d3..b3bdd2aad738 100644
--- a/sdk/eventgrid/azure-eventgrid/tests/test_eg_publisher_client.py
+++ b/sdk/eventgrid/azure-eventgrid/tests/test_eg_publisher_client.py
@@ -145,7 +145,7 @@ def test_send_event_grid_event_dict_data_dict(self, eventgrid_topic_endpoint):
     def test_send_event_grid_namespace(self, **kwargs):
         eventgrid_endpoint = kwargs["eventgrid_endpoint"]
         eventgrid_topic_name = kwargs["eventgrid_topic_name"]
-        client = EventGridPublisherClient(eventgrid_endpoint, AzureKeyCredential(kwargs["eventgrid_key"]), namespace_topic=eventgrid_topic_name)
+        client = self.create_eg_publisher_client(eventgrid_endpoint, eventgrid_topic_name)
         eg_event = {
             "subject": "sample",
             "data": {"key1": "Sample.EventGrid.Event"},
diff --git a/sdk/eventgrid/azure-eventgrid/tests/test_eg_publisher_client_async.py b/sdk/eventgrid/azure-eventgrid/tests/test_eg_publisher_client_async.py
index f91b0e4aa257..760e7e81e9d6 100644
--- a/sdk/eventgrid/azure-eventgrid/tests/test_eg_publisher_client_async.py
+++ b/sdk/eventgrid/azure-eventgrid/tests/test_eg_publisher_client_async.py
@@ -131,7 +131,7 @@ async def test_send_event_grid_event_dict_data_bytes(self, eventgrid_topic_endpo
     async def test_send_event_grid_namespace(self, **kwargs):
         eventgrid_endpoint = kwargs["eventgrid_endpoint"]
         eventgrid_topic_name = kwargs["eventgrid_topic_name"]
-        client = EventGridPublisherClient(eventgrid_endpoint, AzureKeyCredential(kwargs["eventgrid_key"]), namespace_topic=eventgrid_topic_name)
+        client = self.create_eg_publisher_client(eventgrid_endpoint, eventgrid_topic_name)
         eg_event = {
             "subject": "sample",
             "data": {"key1": "Sample.EventGrid.Event"},
diff --git a/sdk/eventgrid/test-resources.json b/sdk/eventgrid/test-resources.json
index 92d9078abce6..d54dbcb65e59 100644
--- a/sdk/eventgrid/test-resources.json
+++ b/sdk/eventgrid/test-resources.json
@@ -38,6 +38,7 @@
       "partnerChannelName": "[concat(parameters('baseName'), 'partner-channel')]",
       "partnerTopicName": "[concat(parameters('baseName'), 'partner-topic')]",
       "eventGridDataSenderRoleId": "d5a91429-5739-47e2-a06b-3470a27159e7",
+      "eventGridDataContributorRoleId": "1d8c3fe3-8864-474b-8749-01e3783e8157"
     },
     "resources": [
       {
@@ -218,8 +219,17 @@
           "principalId": "[parameters('testApplicationOid')]",
           "scope": "[resourceGroup().id]"
         }
+      },
+      {
+        "type": "Microsoft.Authorization/roleAssignments",
+        "apiVersion": "2019-04-01-preview",
+        "name": "[guid(resourceGroup().id, parameters('testApplicationOid'), variables('eventGridDataContributorRoleId'))]",
+        "properties": {
+          "roleDefinitionId": "[resourceId('Microsoft.Authorization/roleDefinitions', variables('eventGridDataContributorRoleId'))]",
+          "principalId": "[parameters('testApplicationOid')]",
+          "scope": "[resourceGroup().id]"
+        }
       }
-
     ],
     "outputs": {
       "EVENTGRID_TOPIC_KEY": {