45 known error codes for this model

10001 Easy Fix

Twilio account is not active and cannot process requests.

10002 Easy Fix

Trial account attempted to use a premium feature.

10003 Easy Fix

Incoming call was rejected due to inactive account.

10004 Moderate

Call concurrency limit exceeded for account.

10005 Easy Fix

Voice calling is disabled for this account.

11100 Easy Fix

Invalid callback URL format in Twilio request.

11200 Moderate

Twilio failed retrieving external URL (HTTP retrieval failure).

11201 Moderate

TCP connection timed out during Twilio callback retrieval.

11202 Moderate

TCP connection was refused when Twilio tried callback URL.

11203 Moderate

Total HTTP communication timeout reached.

11205 Moderate

HTTP connection failed while Twilio requested callback URL.

11206 Easy Fix

HTTP protocol violation detected for callback endpoint.

11210 Easy Fix

HTTP hostname is invalid in callback URL.

11215 Moderate

Too many HTTP redirects encountered.

11216 Moderate

Invalid HTTP redirect target encountered.

11217 Moderate

HTTP error response code returned by callback endpoint.

11220 Moderate

SSL/TLS handshake error during callback request.

11235 Moderate

TLS certificate invalid due to domain mismatch.

11236 Moderate

TLS certificate expired on callback endpoint.

11237 Moderate

Certificate chain path could not be validated.

11251 Easy Fix

Fatal protocol violation while processing HTTP callback.

11300 Easy Fix

Invalid template URL provided to Twilio.

11310 Easy Fix

Invalid template token in Twilio template expansion.

11750 Easy Fix

TwiML response body exceeded maximum allowed size.

11770 Moderate

Received empty response body from callback URL.

12100 Easy Fix

TwiML document parse failure.

12101 Easy Fix

Invalid TwiML XML version value.

12102 Easy Fix

TwiML root element must be Response.

12300 Moderate

Invalid Content-Type on callback response.

12301 Easy Fix

Invalid upload Content-Type in Twilio request path.

12400 Call a Pro

Twilio internal failure during request handling.

13223 Easy Fix

Dial operation contains invalid phone number format.

13224 Easy Fix

Dial target number is invalid or unsupported by Twilio.

13225 Easy Fix

Call blocked by Twilio policy controls.

13227 Easy Fix

Geo permissions configuration blocks call destination.

13325 Easy Fix

Gather->Play provided invalid Content-Type.

13621 Easy Fix

Invalid recordingStatusCallbackEvent parameter.

13806 Easy Fix

Invalid client notification URL for Voice client.

14107 Moderate

SMS send rate limit exceeded.

14222 Call a Pro

TaskRouter enqueue failed creating task.

400 Easy Fix

Twilio request failed as a bad request.

403 Easy Fix

Twilio request was forbidden due to authorization constraints.

404 Easy Fix

Requested Twilio resource could not be found.

410 Easy Fix

Twilio resource is gone and should not be retried as-is.

503 Call a Pro

Twilio internal service error occurred.