Rate this page:

Error 21703

Product: Programmable SMS

ERROR - 21703

The Messaging Service does not have a phone number available to send a message

None of the senders or numbers in your Messaging Service are capable of sending the requested message to this recipient.

Possible causes vary depending on the type of message and the country of the destination number. Below are several common causes of this error.

Possible Causes

  • You attempted to send a message to a United States or Canada mobile number, but you do not have any US/Canada numbers or short codes in your Messaging Service. US/Canada mobile numbers are not reachable from Twilio numbers from outside the US/Canada, due to limitations imposed by carriers.
  • You only have a short code number in your Messaging Service, and the recipient is not reachable from your short code (for example, the To number is from a different country than your short code, or is on a carrier that does not support short code messaging).
  • You attempted to send an MMS message, but you do not have any US/Canada long code numbers or an MMS-enabled short code in your Messaging Service.
  • You only have an Alphanumeric Sender ID in your Messaging Service, and the To number is in a country where Alphanumeric Sender ID is unsupported.

Possible Solutions

  • Add a sender to your Messaging Service with the required capabilities, using the Twilio Console or the REST API.
Rate this page:

Thank you for your feedback!

Please select the reason(s) for your feedback. The additional information you provide helps us improve our documentation:

Sending your feedback...
🎉 Thank you for your feedback!
Something went wrong. Please try again.

Thanks for your feedback!

Refer us and get $10 in 3 simple steps!

Step 1

Get link

Get a free personal referral link here

Step 2

Give $10

Your user signs up and upgrade using link

Step 3

Get $10

1,250 free SMSes
OR 1,000 free voice mins
OR 12,000 chats
OR more