Message blocked

• The destination number you are trying to reach is blocked from receiving this message.
• The device you are trying to reach does not have sufficient signal.
• The device cannot receive SMS (for example, the phone number belongs to a landline).
• The destination number is on India's national Do Not Call registry.
• There is an issue with the mobile carrier.
• You have sent a message from a US/CA Toll-free number to an end user handset that has previously responded with "STOP" or another opt-out keyword .

The first step to troubleshooting this issue is to attempt to replicate the problem. Attempt to send another test message to this user via a REST API request or through the API Explorer in the Twilio Console.

If you see similar results, continue troubleshooting with the following checklist:

• Is the destination device powered on?
• Does the device have sufficient signal? If not, power the device off, then wait 30 seconds and then power it back up.
• Is the device connected to the home carrier's network? We cannot guarantee message delivery to devices roaming off-network.
• Can the device receive non-Twilio SMS?
• Can the device receive messages from another Twilio number (not using an Alphanumeric Sender ID ), or with a shorter one-segment (non- concatenated ) body?
• Can other devices using the same mobile carrier receive your messages?

If you can rule out all of the above issues, continue troubleshooting below.

Error 30004 results on undelivered messages sent to India could be due to the destination number being listed on the national Do Not Call (DNC) registry.

For more information on sending messages to India, including links for updating DNC settings, please see our help center article on limitations for sending SMS to India.

Repeated messages with a Failed status and error 30004 results indicate Twilio may be filtering some of your messages internally.

This filtering is in place to help protect our customers, and the rules attempt to match what we have observed from the industry. For more details, including potential workarounds, please see our help center article "How Does Carrier Filtering Work?"

Twilio's support team can help investigate what went wrong with delivering your message. Please collect 3 or more message SIDs in your SMS logs from the last 24 hours that were flagged with Error 30004, and open a support request.