The most common reason your Sender ID may have been rejected because the Sender ID has already been registered by another user.
Other reasons may include inappropriate or offensive Sender ID names or not adhering to the proper alphanumeric Sender ID requirements.
If you’re using an alphanumeric (custom word) Sender ID, you must ensure that:
Your sender ID is no longer than 16 digits or 11 alphanumeric characters
Only (a-z) and (0-9) characters are used
Any full stops or spaces are removed
Note: Some carriers will reject either alphanumeric or numeric Sender IDs. Please try restrict your Sender ID to either numbers or letters (not both) to see if the problem is resolved. Further information available in Global Sender ID Support.
If you need further assistance please create a ticket below to our support team to help troubleshoot this issue.