How STOP and Opt-Out Works

Both Twilio and Telnyx automatically enforce STOP requests at the carrier level, by default, on every number — this isn't something TelBuddy has to build or turn on. If a customer replies STOP (or a close variant), the carrier blocks all future texts to that number from that Twilio or Telnyx number and sends them a confirmation automatically.

On top of that carrier-level enforcement, TelBuddy adds two things: an opt-out line ("Reply STOP to unsubscribe") automatically appended to the first message you ever send a number that's never texted in — not cluttering every reply once a real conversation is underway — and a plain-language "this customer opted out" message in place of a raw API error if you try to text someone who's blocked you.

If you need to reach that customer again after they've opted out, they'll need to text START (or a similar keyword) to the same number first.