TSS can send SMS text messages and reminders via email relay for AT&T, Sprint, T-Mobile, and Verizon.

First go to application settings, then Email & SMS, verify you have your email settings correctly configured, and enable prompt for carrier. See How to Configure Email settings with TSS XP for more details.

You can send a SMS text message directly from the invoice screen under the functions menu

You can also send appointment reminder messages from the functions menu to all customers with cell numbers and carriers within a date range from the schedule screen.