Many times businesses obtain consent to send messages via Web forms, emails or offline methods like contracts. Many industry bodies and associations like the TCPA recommend confirming the Opt-in via handset by sending an explicit SMS asking to confirm or at least notify the recipient that they are subscribed to the text message service from your business. 

The consent status of the recipients is set to pending until they use this keyword to confirm the request. On receiving the keyword from the prospect, you send a response confirming the consent. This completes the compliance process. For more information about configuring double opt-in, see Configure Double Opt-in.