Issue

You may report that status callbacks configured in your Messaging Service are not being received when sending outbound messages through the API.

Product

Programmable Messaging

Environment

legacy Twilio Console

Cause

Even though the callback URL is correctly set under Messaging → Services → [Service] → Integration → Status Callback URL, no delivery status events (e.g., queued, sent, delivered, failed) are triggered at that endpoint.

When creating messages through the Twilio API, you can specify:

• A specific phone number using the from parameter
• A Messaging Service using the messaging_service_sid parameter,
• Or both together.

If the messaging_service_sid is not included, the message is sent directly from the phone number, and Twilio will send status callbacks to the callback URL configured for that phone number, if one exists.

In this case, the Messaging Service’s callback URL is not used, even if the number belongs to the Messaging Service.

Resolution

To ensure status callbacks are sent to the Messaging Service’s callback URL, include the messaging_service_sid parameter when creating your messages.

You may still include the from parameter to specify which sender in the Messaging Service should be used, but the Messaging Service configuration will take precedence for callbacks and routing behavior.

Example

Incorrect Implementation

This message uses a phone number directly, so the Messaging Service callback will not be triggered:

from twilio.rest import Client

client = Client(account_sid, auth_token)

message = client.messages.create(
    from_="+14155551234",
    to="+14155556789",
    body="Hello! This message may not trigger your Messaging Service callback."
)

Correct Implementation

Including the messaging_service_sid ensures that callbacks go to your Messaging Service:

from twilio.rest import Client

client = Client(account_sid, auth_token)

message = client.messages.create(
    messaging_service_sid="MGXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX",
    from_="+14155551234",  # Optional - must belong to the Messaging Service
    to="+14155556789",
    body="Hello! This message will use your Messaging Service callback."
)

Additional Information 

• Using both from and messaging_service_sid is valid, the Messaging Service configuration determines callback behavior.
• You can configure the Messaging Service status callback URL in the Twilio Console under:
  Messaging → Services → [Your Service] → Integration → Status Callback URL
• Reference: Create a Message Resource.

If you rely on Messaging Service callbacks, always include the messaging_service_sid parameter when sending outbound messages. This ensures consistent delivery reporting and that callbacks are sent to the intended endpoint.