Opt-In

Opt-in refers to the process by which a customer gives explicit consent to receive marketing communications from a business. For SMS marketing in the United States, written opt-in consent is legally required under the Telephone Consumer Protection Act (TCPA) before any marketing text can be sent. For email, opt-in is a best practice that produces better results even where it is not legally mandated. Sending messages to people who have not opted in is not only legally risky — it produces poor results because recipients are more likely to mark messages as spam.

Single vs. Double Opt-In

Single opt-in: the customer provides their contact information and is immediately added to your list. Double opt-in: after providing their information, the customer must confirm their subscription via a second action — clicking a link in a confirmation email or replying YES to a confirmation text. Double opt-in produces smaller but significantly higher-quality lists — fewer typos, fewer inactive addresses, and higher engagement rates — because only genuinely interested people complete the second step.

SMS Opt-In Requirements

For SMS marketing under TCPA, opt-in must be: in writing (including electronic), voluntary, and include clear disclosure of what the customer is consenting to (message frequency, message type, the fact that standard message and data rates may apply). The opt-in cannot be buried in fine print or made a condition of purchasing. Violations can result in fines of $500–$1,500 per message — making compliance non-negotiable.

Best Practices

Collect opt-ins at every natural touchpoint: in-person sign-up forms, website checkout, app onboarding, and in-store tablets. Make the value proposition clear — “Sign up for SMS alerts and get early access to promotions” — so customers understand what they are agreeing to. Store opt-in records (when, where, and how consent was given) in case you ever need to demonstrate compliance.