An Alphanumeric Sender ID is your company name or brand used as the Sender ID in one-way SMS messages sent to supported countries. Alphanumeric Sender IDs may be up to 11 characters long. Accepted characters include both upper- and lower-case Ascii letters, the digits 0 through 9, and the space character. They may not be only numerals.
Not all countries support Alphanumeric Sender IDs, and many that do require you to register your Alphanumeric Sender ID before it is first used. Here is a list of countries that support Alphanumeric Sender IDs which includes the pre-registration requirements for each one.
You can add Alphanumeric Sender IDs to a Messaging Service. When you send SMS messages to a supported country, your Twilio Messaging Service will set your Alphanumeric Sender ID as the From parameter to deliver your message. When you send SMS messages to a country where Alphanumeric Sender IDs are not supported, Twilio will use a regular phone number from your messaging service.
In order to use Alphanumeric Sender IDs with your Messaging Service, Alphanumeric Sender ID must be enabled in your Account's SMS Settings. For more information on how to use Alphanumeric Sender ID with Messaging Services, please see our support article.
To learn more, see Getting Started with Alphanumeric Sender ID.