To upgrade your SMS free trial to a premium billed account:
Go to Campaigns > SMS.
Select You're currently on an SMS trial. Upgrade now. from the top of the page.
Follow the on screen instructions.
Next steps
Once you’ve reached the end of your SMS trial, you need to upgrade to start using SMS in a real, live environment.
To upgrade your SMS free trial to a premium billed account:
Go to Campaigns > SMS.
Select You're currently on an SMS trial. Upgrade now. from the top of the page.
Follow the on screen instructions.