The system does not automatically include an unsubscribe link or text in an SMS.

The Opt Out / Unsubscribe process will depend on whether you send from an actual mobile number as your sender ID or use an alpha numeric sender ID (which cannot be replied to directly) on how the process should be addressed.

When using a mobile number include "Reply Stop to opt out" or if using an Alpha Numeric ID (ie MyAgency) include "Reply Stop to [your mobile number] to opt out."

Whoever receives the SMS will need to manually unsubscribe the contact.