If a message you sent is not delivered to the end device and returns a 30006 error code, this means that delivery of your message failed due to the destination being a landline and incapable of receiving SMS, or an unreachable destination carrier.
Troubleshooting Steps for Error 30006
First, check whether the destination (To) number is a landline number, using the Lookups API.
By default, Twilio will attempt delivery for long code SMS to landline numbers in the US, Canada, and UK. Landlines in these countries are sometimes SMS-enabled, however if you see repeated delivery errors to a landline number, we recommend removing that number from further SMS sending.
You can also choose to override Twilio's default behavior and prevent SMS from being attempted to landline numbers in the US, Canada and UK. To do this, pass the extra parameter "forceDelivery=false" in your API requests to send messages.
Next troubleshooting steps if the "To" number is not a landline
- 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?
In some cases a delivery error may occur once due to a transient issue downstream of Twilio. To test whether the issue occurs again, you can attempt to send another test message to the user via a REST API request, or through the API Explorer in Console.
Continued Error 30006 Issues
If you can rule out the above issues, 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 30006, and Open a support request.