Glossary

Opt-in

Definition

An opt-in is a person's permission to receive messages from an organization, given through an action they take themselves, such as texting a keyword, ticking a box, or submitting a sign-up form. It's the record that someone asked to hear from you.

Updated November 3, 2026

What is an opt-in?

An opt-in is a person's permission to receive messages from an organization, given through an action they take themselves. Texting a keyword to a short code, ticking a box on a form, submitting an email address, or replying YES to a question are all opt-in actions. In email and texting, the opt-in is the record that someone asked to hear from you, and the starting point for most consent rules.

The opposite approach is opt-out, where people are contacted until they ask to stop. Rules for text messages in the US lean heavily toward opt-in, especially for marketing messages.

How does it work?

A clear opt-in has three parts:

  1. An action by the person. They do something deliberate: text the keyword, scan and send, fill in the form. Pre-ticked boxes and lists bought from someone else don't count as their action.
  2. A clear description of what they're agreeing to. "Text DEMO to 33777 to get today's slides" tells people what they'll get. If you also plan to add them to a newsletter, say so.
  3. A record. The organization keeps proof of when and how the person signed up.

Opt-in comes in two common forms. A single opt-in adds the person after one action. A double opt-in asks them to confirm again, usually by clicking a link in an email, before they're added.

Different kinds of messages carry different consent requirements, and in the US the TCPA and carrier guidelines set the expectations for texts. Email has its own rules. This page is a definition and not legal advice; for your situation, talk to a lawyer. Is text-to-join legal? covers the basics.

Every opt-in also needs a way back out. For texts that's STOP; for email it's the unsubscribe link.

Why it matters at live events

At a live event, the opt-in usually happens in seconds. A speaker puts a keyword on the screen, a church prints a QR code on the bulletin, a band says "text JOIN to 55444" from the stage. The person decides on the spot, so the call to action has to say plainly what they'll get. "Text SLIDES to get the slides and my weekly email" is clearer than "Text SLIDES to stay connected."

Text-to-join has a useful property here: the person sends the first message. With Textiful, people start the conversation themselves. STOP and HELP are handled automatically. Once a flow adds someone to your email list, your follow-up comes from your email tool, so match your promise on stage to what your emails will be.

Key takeaways

  • An opt-in is permission to receive messages, given by an action the person takes.
  • A good opt-in says plainly what the person will receive, and is recorded.
  • Single opt-in takes one action; double opt-in asks for a confirmation.
  • For legal questions about consent, ask a lawyer.

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