Twilio Verify Error - "Guardian - Error on send-phone-message-hook: 60204 Custom code not allowed"

Additional ExtensibilityEmail, Voice, SMS Integrations

Last Updated: Sep 10, 2025

Overview

When attempting to configure and test Twilio Verify, an error occurs with the description:

Guardian - Error on send-phone-message-hook: 60204 Custom code not allowed

Example of what the tenant log might shows:

{
"date": "[...]",
"type": "gd_send_sms_failure",
"description": "Guardian - Error on send-phone-message-hook: 60204 Custom code not allowed",
"ip": "[...]",
"user_agent": "[...],
"user_id": "[...]",
"details": {
"request": {
"method": "POST",
"path": "/api/sms/configs/[...]/authenticators/[...]/challenge",
"query": {},
"userAgent": "[...]",
"body": {
"client_id": "[...]",
"render_locale": "[...]",
"originHost": "[...]",
"is_free_tenant": "[...]"
},
"ip": "...",
"auth": {
"strategy": "jwt_api2_internal_token_with_tenant",
"scopes": [
"..."
]
}
},
"response": {},
"enrollment": {},
"failure_details": {
"errorCode": 60204,
"message": "Custom code not allowed"
},
"actions": {
"executions": [
  "nkxHQyu6TZy5_OdPsHTRuTIwMjQwNTE2"
]
},
"device_id": "..."
},
"log_id": "...",
"_id": "...",
"isMobile": ...,
"id": "..."
}

Cause

This error comes from Twilio and occurs when an SMS with a custom message is sent to an account that does not have Custom Messages enabled on the Twilio side.

See more details in the following Twilio documentation: custom_message_not_allowed.

Solution

Please reach out to Twilio Support for any assistance in enabling Custom Messages.

While, at the moment, there is no out-of-the-box integration for Twilio Verify, Twilio has a guide to set it up at the following link: How to configure Auth0 MFA using Twilio Verify.

Related References

How to configure Auth0 MFA using Twilio Verify