Texting customers is legal — and it works far better than email for things like review requests and appointment reminders. But there are real rules, and getting them wrong can mean real fines. Here's the plain-English version.
The short version
In the U.S., the Telephone Consumer Protection Act (TCPA) governs commercial text messages. The core rule: you need the recipient's consent before texting them for marketing or promotional purposes. Consent isn't just a technicality — it's the entire legal foundation that makes texting customers okay.
What counts as valid consent
The clearest, safest form is the customer directly giving you their number and agreeing to be contacted by text — for example, checking a box when you add them to your system, or replying to an opt-in request. Simply having someone's number from a past transaction (like an invoice) isn't automatically the same as consent to text them promotional messages.
Every message needs an easy opt-out
Every commercial text should make it clear the recipient can reply STOP to unsubscribe, and that opt-out has to actually work — immediately, without requiring a phone call or extra steps. This isn't optional; carriers and the FCC both take it seriously, and ignoring an opt-out request is one of the more common violations that leads to complaints.
A2P 10DLC registration (the part most people have never heard of)
If you're sending business texts through a platform (rather than manually from your own phone), your business typically needs to be registered through a process called A2P 10DLC ("Application-to-Person 10-Digit Long Code") with the carriers. This isn't a scam or an upsell — it's the legitimate registration system carriers use to distinguish real business messaging from spam, and it affects deliverability even when everything else is done right.
What this looks like in practice for a small business
- Get explicit consent when you add a customer's phone number — a simple checkbox is enough, as long as it's clear what they're agreeing to
- Include a way to opt out in every message, and honor STOP replies immediately and automatically
- Don't buy or scrape phone number lists — consent has to come from the actual person
- Keep records of consent, in case it's ever questioned
Done right, texting is one of the most effective tools a small business has — it just has to be built on consent from the start, not bolted on as an afterthought.