Select an Agent from Setup > Accounts. Once inside the agent’s information, click the “SMS Messaging” tab.
You will see a list of this account's active and previously activated SMS numbers.
To add a new SMS number, click the Activate a Number button.
You can select various search criteria to narrow down your choices for a number.
You can use the Area Code, City, or even digits within the phone number. Toll-free numbers are not available for use.
Once you activate a phone number, you may not deactivate it for one month.
If you deactivate a phone number, it is impossible to reactivate it.