Text messages get read. That is why they work for reminders, follow-ups and offers, and it is why regulators everywhere treat them more strictly than email. In the US especially, the penalties for texting people without proper consent are per message, and the lawsuits are routine. The good news is that SMS marketing compliance for a small business comes down to five rules that hold almost everywhere, and a platform that does most of the work if you set it up properly.
This is the plain-English version — it is guidance from someone who sets these systems up, not legal advice, and the specific law where you operate (TCPA and state laws in the US, PECR in the UK, CASL in Canada, the Spam Act in Australia) is what actually applies. Registration is a separate topic covered in the A2P guide; this article is about what you send and to whom.
Marketing or transactional? Decide first
| Type | Examples | What it needs |
|---|---|---|
| Transactional / informational | Appointment confirmation and reminder, “your order has shipped”, “your quote is ready”, a reply to their enquiry | A reasonable expectation from the customer’s action; identification; an opt-out still recommended |
| Marketing / promotional | Offers, seasonal promotions, “we have availability”, review requests with incentives, newsletters | Prior express written consent, identification, opt-out in the message, sent in permitted hours, records kept |
The trap is the hybrid: a reminder with an offer stapled on (“Your service is Tuesday — and 15% off a new thermostat!”). That is a marketing message and needs marketing consent. Keep the two kinds separate in your workflows.
Rule 1: Consent you can prove
For marketing texts you need the person to have clearly agreed to receive them, and you need to be able to show it. Acceptable forms:
- An unticked checkbox on a web form with disclosure text next to it (below).
- A keyword texted to your number (“Text OFFERS to…”), followed by a confirmation.
- A signed form or a recorded verbal agreement, logged in the CRM with the date.
Not acceptable: a phone number typed into a contact form with no mention of texting; a number from a bought list; a number from someone who once called; a pre-ticked box. Consent is for your business only, and it does not transfer.
Consent language that holds up
☐ Yes, text me. By ticking this box I agree to receive appointment reminders and occasional offers by SMS from Example Co. at the number provided. Consent is not a condition of purchase. Message frequency varies. Message and data rates may apply. Reply STOP to opt out at any time, HELP for help. See our Privacy Policy and SMS Terms.
Then send a confirmation the moment they opt in — it doubles as the record:
Example Co.: You’re signed up for reminders and offers by text. Msg frequency varies, msg & data rates may apply. Reply STOP to opt out, HELP for help.
Rule 2: Say who you are
Every message identifies the business, ideally at the start. People do not save your number; a text that begins “Hi! Big news…” from an unknown number is spam to them and a complaint to the carrier.
Rule 3: Opt-out that works instantly
- Marketing messages carry the instruction: “Reply STOP to opt out.” Short form (“Txt STOP to end”) is fine.
- STOP, UNSUBSCRIBE, CANCEL, END and QUIT must all stop messages automatically, immediately, without a human. Platforms handle this, but test it with your own phone.
- Send one confirmation of the opt-out and nothing else afterwards. Not even “sorry to see you go” a week later.
- Honour opt-outs made any other way too — a reply saying “please stop texting me”, an email, a phone call — by marking the contact do-not-text in the CRM.
- HELP should return the business name, a contact method and how to opt out.
Rule 4: Timing and frequency
Marketing texts go out in the recipient’s local daytime — the common US federal window is 8am to 9pm, and some states narrow it; other countries have similar expectations. Schedule broadcasts for mid-morning or early afternoon, by the contact’s time zone if your platform supports it. Frequency: state it at opt-in (“up to 4 msgs/month” or “frequency varies”) and stay well inside what a reasonable customer expects. A weekly promotional text from a plumber is not what anyone signed up for.
Transactional messages follow the event — a reminder 24 hours before an appointment lands whenever that is — but avoid the middle of the night for anything that is not urgent.
Rule 5: Records
For every contact: how they consented, when, from where (form URL, keyword, in person), the exact disclosure they saw, and every opt-out. Your CRM holds this if you build it in — a source tag, a consent date field, the platform’s message log. Keep it for several years. If a complaint ever arrives, this record is the entire defence.
Sample messages that comply
Transactional
Example Co.: Reminder — your appointment is tomorrow (Tue 14 May) at 10:00, 12 High St. Reply C to confirm or R to reschedule. Reply STOP to opt out.
Example Co.: Your quote #1042 is ready: https://example.com/q/1042. Questions? Reply here or call 0161 000 0000.
Marketing (consent on file)
Example Co.: Spring boiler service — £85 for existing customers until 31 May. Book: https://example.com/book. Reply STOP to opt out.
Example Co.: We have two slots left this week if the leak you mentioned is still bothering you. Reply YES and we’ll call. Reply STOP to opt out.
Missed-call text-back
Example Co.: Sorry we missed your call. Reply here with what you need and we’ll call back within 10 minutes. Reply STOP to opt out.
The missed-call workflow is generally treated as a response the caller expects — keep it to the enquiry, no offers, and get marketing consent separately if you want to promote to them later.
Setting it up in the CRM
- Two tags:
sms-transactional-ok(set by a booking or enquiry) andsms-marketing-consent(set only by the checkbox, keyword or logged agreement), plus a consent date field. - Marketing workflows and broadcasts filter on the marketing tag; reminder workflows on the transactional one.
- STOP handling switched on (it usually is by default), tested, and a do-not-text tag applied by any opt-out.
- Quiet-hours window set on marketing sends; time zone per contact where possible.
- Every marketing template ends with the opt-out line; every template starts with the business name.
- Consent language on every web form that collects a phone number, and the privacy policy updated to match (the campaign rejection guide has the paragraph).
The mistakes that cause complaints
- Texting every number in the CRM because “they’re our customers”.
- Promotions inside reminders.
- Late-evening broadcasts.
- A STOP that goes to a human inbox and is handled on Monday.
- No business name in the message.
- Consent collected for one business and used by another (agencies, take note).
The one-line test for any message: would this person, seeing it on their phone at this moment, know who it is from, remember agreeing to it, and know how to stop it? If any answer is no, fix the message or the consent before sending.
Further reading: FCC: unwanted calls and texts · CTIA messaging principles.
FAQ
Do I need consent to text customers?
For marketing texts, yes, almost everywhere, and in the US it needs to be express written consent — a ticked box, a keyword, a signed form — kept on record. Transactional texts about something the customer asked for (an appointment they booked, an order they placed) are treated more leniently but still need an opt-out.
What has to be in an opt-out?
Every marketing text should say how to stop (usually “Reply STOP to opt out”), the STOP keyword must work immediately and automatically, and a confirmation is sent once. Most platforms handle the standard keywords — STOP, UNSUBSCRIBE, CANCEL, END, QUIT — but you should test them.
When am I allowed to send marketing texts?
Within the recipient’s local daytime — the common US rule is 8am to 9pm, and some states are stricter. Schedule broadcasts for mid-morning or early afternoon, and let transactional messages (reminders, confirmations) follow the appointment, not the clock.
Is a missed-call text-back a marketing message?
A reply to someone who just called you is generally treated as a response the caller expects, not marketing — but keep it to the enquiry, include the opt-out line, and do not add offers. If you later want to send that person promotions, get consent first.
Want the consent forms, tags, workflows and templates set up so compliance is built in rather than remembered? See the SMS and A2P services — it is part of every messaging build I do, because the alternative is expensive.
