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Error 30005 "Message Delivery - Unknown destination handset" when Sending SMS

If a message you sent is not delivered to the end device and returns a 30005 error code, this means that delivery of your message failed due to an unknown or inactive destination number, for example a number that is no longer in service.

Troubleshooting Steps for Error 30005

If possible, first verify that the destination (To) number is a valid mobile number with active mobile service. If some time has elapsed since the mobile user provided their number to you, it is possible that the user has deactivated the number or their mobile service account has lapsed.

If the mobile user provided their number to you recently, or you are in direct contact with the user and they can confirm their number is valid and active, please check the following troubleshooting items:

  • Check the Twilio Status Page to see if an active incident could be causing your issues.
  • Is the destination device powered on?
  • Does the device have sufficient signal? If not power the device off, wait 30 seconds, and then power it back up.
  • Is the device connected to the home carrier's network? We cannot guarantee message delivery on devices roaming off-network.
  • Can the device receive non-Twilio SMS?
  • Can the device receive messages from another Twilio number (non-Alphanumeric Sender ID), or with a shorter one-segment (non-concatenated) body?
  • Can other devices using the same mobile carrier receive your messages?
  • If the recipient is on T-Mobile, please confirm that they do not have message blocking enabled. See T-Mobile's Message Blocking below.

In some cases, a delivery error may occur once due to a transient issue downstream of Twilio. To test whether the issue occurs again, please send another message to the user via a REST API request. Pay close attention to your request, and double check to verify you are attempting to send messages to the correct phone number using valid E.164 formatting.

Continued Error 30005 Issues

If you can rule out all of the above issues, Twilio's Support team can help investigate what went wrong with delivering your messages. Please collect 3 or more Message SIDs in your SMS logs from the last 24 hours that were flagged with Error 30005, and Open a support request.

T-Mobile's Message Blocking

T-Mobile has a feature that allows recipients on their network to enable a setting which blocks ANY SMS sent to their mobile number from business-type sender numbers, such as Short Codes, Toll-Free, and 10DLC-Routed Long Codes. This includes OTP codes, appointment notifications, etc. from any sender network. This is not a Twilio-specific limitation.

SMS sent to T-Mobile recipients with this feature enabled often returns error 30005 in the SMS logs, indicating the block. This can only be removed by having the recipient contact T-Mobile Support directly to request that setting be turned off. Specifically, the mobile user must call 611 directly from their T-Mobile device experiencing the issue – or if using another device, call 1-800-937-8997 – and request "Shortcode Blocklist" setting to be removed from their account.

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