How to Handle STOP and Unsubscribe Requests Automatically
Why Automatic STOP Handling Matters
Failing to honor opt-out requests is one of the most common TCPA violations and one of the easiest to prove in court. The subscriber has a text record showing they sent STOP, and if you send another message after that, you have clear liability. Automatic handling eliminates human error and ensures every opt-out is processed instantly, even if you are asleep or on vacation when the reply comes in.
Carriers also monitor opt-out compliance. If carriers detect that your number continues sending to recipients who have opted out, they will flag your number for filtering or outright blocking. See how to avoid getting blocked for more on carrier enforcement.
Step-by-Step Setup
In your SMS settings, enable opt-out keyword detection. The platform recognizes the five CTIA-mandated opt-out keywords: STOP, CANCEL, UNSUBSCRIBE, QUIT, and END. These are checked case-insensitively, so "stop," "Stop," and "STOP" all trigger the opt-out process.
Set up an automatic reply that gets sent when someone opts out. The standard response is: "You have been unsubscribed from [Business Name] and will receive no further messages. Reply START to resubscribe." Keep this message short and factual. This confirmation is allowed under the TCPA even though the person just opted out, because it is a one-time transactional confirmation of their request.
When a STOP keyword is detected, the platform automatically adds the phone number to your suppression list. This list is checked before every send, ensuring no future campaigns or drip sequences reach that number. The suppression list persists until the subscriber explicitly opts back in (typically by texting START or JOIN).
Beyond the five standard keywords, consider handling common variations that subscribers might send: "Please stop," "Remove me," "Take me off," "No more," or "Opt out." While only the five standard keywords are legally required, handling these variations improves the subscriber experience and reduces complaint risk. The platform can be configured to recognize custom keywords.
Before launching campaigns, test the opt-out flow end to end. Send yourself a message, reply STOP, verify you receive the confirmation, and then try sending another campaign to confirm your number is suppressed. Test all five standard keywords to make sure each one triggers the opt-out correctly.
Re-subscription (START / JOIN)
When a previously unsubscribed contact texts START, JOIN, or YES to your number, the platform can automatically remove them from the suppression list and send a re-subscription confirmation. The re-subscription confirmation should include the same disclosure language as a new opt-in: business name, message frequency, data rates notice, and how to opt out again.
Important: you should only re-subscribe contacts who take this explicit action. Never manually remove someone from the suppression list without a clear re-opt-in from them.
Suppression List Best Practices
- Never delete your suppression list. Even if you switch platforms, export and import your suppression list to ensure previously opted-out numbers remain suppressed.
- Cross-channel suppression. If someone opts out of SMS, do not add them back through a different opt-in channel without clearly separate consent.
- Audit regularly. Review your suppression list growth rate. If more than 3-5% of subscribers opt out per campaign, your message frequency or content relevance needs adjustment.
- Keep records. Log the date, time, and keyword used for every opt-out and opt-in event. This documentation protects you in disputes.
Set up automatic opt-out handling and send SMS campaigns with confidence.
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