Messaging Error Codes

Messages with a delivery receipt indicating a failure will be tagged with a code indicating the cause of the failure. You can use this to identify when messages haven't gone through and understand why.

In the v1 API, the status of these messages may be any of failed, gw_reject, or gw_timeout.

In the v2 API, the status of these messages may be any of delivery_failed or expired.

A code and title in the table below will be included on the Message Detail Record (MDR) sent to a webhook or requested via the API in the errors field.

Code	Title	Description
40001	Not routable	The destination number is either a landline or a non-routable wireless number.
40002	Blocked as spam - temporary	The message was flagged by a SPAM filter and was not delivered. This is a temporary condition.
40003	Blocked as spam - permanent	The message was flagged by a SPAM filter and was not delivered. The originating phone number is permanently blocked.
40004	Rejected by destination	The recipient server is rejecting the message for an unknown reason.
40005	Message expired during transmission	The message expired before it could be fully delivered to the recipient. This error occured after the message left Telnyx and was en route to the destination.
40006	Recipient server unavailable	The recipient server is unavailable or not responding. This may be a temporary issue.
40007	Loop detected	Infinite loop detected.
40008	Undeliverable	The recipient carrier did not accept the message. This is a general purpose undeliverable message.
40009	Invalid message body	The message body was invalid. The rules Telnyx uses to allow messages may not align with all carriers at all times. If the destination carrier uses more stringent rules, they may reject messages.
40011	Too many requests	Exceeded upstream rate limit. As a result the message was flagged by a SPAM filter and was not delivered. This is a temporary condition.
40012	Invalid messaging destination number	The destination phone number was deemed invalid by the carrier.
40013	Invalid messaging source number	The source phone number was deemed invalid by the carrier.
40014	Message expired in queue	The message expired in the queue. This error occured before Telnyx attempted to relay your message, and you were not billed.