diff --git a/example.env b/example.env
index 5d8a9d6..b4c5c15 100644
--- a/example.env
+++ b/example.env
@@ -4,6 +4,7 @@ TO_NUMBER='EXAMPLE_TO_NUMBER'
 RECIPIENT_NUMBER='EXAMPLE_RECIPIENT_NUMBER'
 FROM_NUMBER='EXAMPLE_FROM_NUMBER'
 NEXMO_BRAND_NAME='Acme Inc.'
+NEXMO_APPLICATION_ID='12a3b4cd-a1b2-1ab2-a1b2-a1234bc5d678'
 
 # Number Insight examples
 INSIGHT_NUMBER='NUMBER_FOR_INSIGHT'
@@ -18,7 +19,6 @@ NUMBER_SEARCH_PATTERN=1
 NEXMO_NUMBER='447700900001'
 NEXMO_NUMBER_TYPE='mobile-lvn'
 NEXMO_NUMBER_FEATURES='SMS,VOICE'
-MESSAGES_APPLICATION_ID='12a3b4cd-a1b2-1ab2-a1b2-a1234bc5d678'
 VOICE_CALLBACK_TYPE='tel'
 VOICE_CALLBACK_VALUE='447700900002'
 VOICE_STATUS_URL='https://example.com/webhooks/status'
diff --git a/numbers/update.py b/numbers/update.py
index be5bfcf..491de7c 100644
--- a/numbers/update.py
+++ b/numbers/update.py
@@ -9,7 +9,7 @@
 NEXMO_API_SECRET = os.getenv("NEXMO_API_SECRET")
 NEXMO_NUMBER = os.getenv("NEXMO_NUMBER")
 COUNTRY_CODE = os.getenv("COUNTRY_CODE")
-MESSAGES_APPLICATION_ID = os.getenv("MESSAGES_APPLICATION_ID")
+NEXMO_APPLICATION_ID = os.getenv("NEXMO_APPLICATION_ID")
 VOICE_CALLBACK_TYPE = os.getenv("VOICE_CALLBACK_TYPE")
 VOICE_CALLBACK_VALUE = os.getenv("VOICE_CALLBACK_VALUE")
 VOICE_STATUS_URL = os.getenv("VOICE_STATUS_URL")
@@ -24,8 +24,7 @@
         {
             "msisdn": NEXMO_NUMBER,
             "country": COUNTRY_CODE,
-            "messagesCallbackType": "app",
-            "messagesCallbackValue": MESSAGES_APPLICATION_ID,
+            "app_id": NEXMO_APPLICATION_ID,
             "voiceCallbackType": VOICE_CALLBACK_TYPE,
             "voiceCallbackValue": VOICE_CALLBACK_VALUE,
             "voiceStatusCallback": VOICE_STATUS_URL,