By US FCC regulations, you must allow users to unsubscribe from Text/SMS notifications. CivicReady has shortcodes that send out day-to-day messages and emergency alerts. These shortcodes allow users to unsubscribe as well.
- Emergency Notifications
- Day-to-Day Notifications
With text messages, they can just reply to any message they receive with the word STOP and they will cease to receive messages from that shortcode. If they would like to resume them, they can simply find one of those messages reply once again to that shortcode with the word RESUME and that will allow them to receive messages again.