SMS opt-in and opt-out are the mechanisms by which people agree to receive business text messages and later withdraw that agreement. Opt-in is the consent a business collects before texting someone, such as a checked box with clear disclosure on a web form or a customer texting a keyword to a number. Opt-out is how the recipient stops the messages, most often by replying STOP. In the US, consent for business texting is shaped by two layers: industry and carrier requirements that decide whether your traffic is carried, and laws such as the Telephone Consumer Protection Act (TCPA) that can expose senders to legal claims.
At a glance
- Opt-in is documented permission to text someone; opt-out is how they withdraw it, commonly by replying STOP.
- HELP is the standard keyword for program information; many providers recognize other opt-out words too.
- In the US, CTIA guidance and carrier codes of conduct are industry requirements enforced by carriers, not laws; the TCPA and other laws apply separately.
- Opt-in details are reviewed during 10DLC registration, toll-free verification and short code approval.
- Requirements differ by country and by message type, with marketing generally held to a higher standard; confirm your program with counsel.
What problem it solves
Text messages are personal and immediate, which makes unwanted ones intrusive. Clear consent and easy opt-out protect recipients from spam and give carriers a way to judge whether a sender’s traffic is wanted.
For businesses, a sound consent process does three jobs. It keeps traffic eligible on registered channels such as 10DLC, it reduces complaints that lead to carrier message filtering, and it lowers legal risk. In the US, TCPA claims over unwanted texts can be costly, and records of how and when someone opted in are central to defending them.
How it works
Collecting opt-in. Common methods include a web or app form, a paper form, a keyword texted to a number, or a verbal request recorded by an agent. Industry guidance generally expects the sign-up point to say who is sending, what kind of messages, roughly how often, that message and data rates may apply, and how to get help and opt out. Consent for one purpose, such as appointment reminders, generally shouldn’t be stretched to cover marketing.
Confirming. Many programs send a confirmation text when someone opts in, repeating the program name, frequency and opt-out instructions. Some use double opt-in, asking the person to reply to confirm.
Recordkeeping. Keep evidence of each opt-in: when, how, what was disclosed and the number. Registrations with The Campaign Registry and toll-free verification submissions commonly ask how consent is collected.
Opt-out. When someone replies STOP or a similar keyword, the sender stops messaging that number on that program. A single confirmation is common. Opt-outs need to sync across systems so a marketing tool, contact center and phone system don’t keep texting someone who said stop. In the US, recent FCC rule changes address how people can revoke consent beyond keywords; ask counsel what currently applies to you.
HELP. A HELP reply returns the program name and a way to get support.
Providers often handle standard keywords automatically, but businesses remain responsible for consent and for honoring opt-outs across systems. If texting runs through your contact center, our CCaaS solutions page explains what to check with providers.
When it matters for buyers
- Launching business texting, when registration reviews ask how people opt in.
- Adding marketing to a service-only messaging program, which may need new consent and a new campaign.
- Running several texting tools, where opt-outs must be shared between systems.
- Responding to a complaint or demand letter, when consent records matter.
Questions to ask vendors
- Which opt-out and help keywords do you handle automatically, and can we customize the replies?
- Are opt-outs enforced across all our numbers and campaigns, and can we sync them with our other tools?
- How do you store opt-in records, and can we export them?
- Will you review our sign-up wording before registration?
- How do you handle opt-outs sent in other words or languages?
- What happens if a message is sent to someone who has opted out?
How it differs from the TCPA
The TCPA is a US law that sets consent requirements for certain calls and texts and allows legal claims when they’re not met. SMS opt-in and opt-out are the practical mechanisms a business uses to collect and honor consent, shaped by both that law and carrier and industry requirements. Meeting carrier expectations doesn’t by itself establish TCPA compliance, and the reverse is also true, so treat them as separate checks.