> For a complete page index, fetch https://docs.synthflow.ai/llms.txt. For full documentation content, fetch https://docs.synthflow.ai/llms-full.txt.

# Extended list of transfer failure reasons

> Failed transfers now report nine specific failure reasons instead of a generic one.

Failed transfers now report more specific failure reasons:

* `number_not_found`
* `number_incomplete`
* `destination_unavailable`
* `rejected_by_destination`
* `transfer_blocked_by_carrier`
* `carrier_unavailable`
* `routing_loop`
* `media_negotiation_failed`
* `transfer_method_unsupported`

Find every state, reason, and SIP code in the [transfer outcome states reference](/transfer-outcome-states).