21709: Alpha Sender ID is Invalid or Not Authorized for this Messaging Service
ERROR: 21709
PROGRAMMABLE SMS
ERROR
Description
The Alpha Sender ID being added to a Messaging Service is invalid or Alpha Sender IDs have not been enabled for this Messaging Service.
Possible Causes
The Messaging Service is not enabled to support Alpha Sender IDs.
The Alpha Sender ID being added to a Messaging Service is invalid. Alphanumeric Sender IDs may be up to 11 characters. They may not be only numbers. Refer to this page for acceptable characters.
Possible Solutions
Follow these steps to verify your Messaging Service is enabled to support Alpha Sender IDs. If it is not, please reach out to Support.
Verify the Alpha Sender ID you are trying to add to the Messaging Service is valid. View formatting requirements here.