SMS Marketing Consent: What Small Businesses Actually Need Before Hitting Send

22 September 2026·5 min read

Quick answer: Having someone's mobile number because they booked, bought or enquired once does not automatically give you the right to send promotional texts. Transactional messages like booking confirmations sit under a lower bar than marketing texts, which generally need proper consent and a working opt-out. Mixing the two — or assuming a booking equals a blank cheque — is where most small businesses get into trouble. 📱

Text messages feel personal, which is exactly why people get annoyed fast when the wrong ones land in their pocket. We've watched small businesses build a beautiful client list in their booking system, then one slow Tuesday blast everyone with "20% off this week only" — and get hit with opt-out replies, complaints, and occasionally real ACMA-adjacent grief. The mistake almost never comes from bad intentions. It comes from treating "I have their number" and "they consented to marketing" as the same thing, when they're not even close. 💖

What most businesses get wrong

The confusion usually starts because SMS feels less formal than email, so people assume the rules are looser too. They're not — SMS marketing sits under the same Spam Act framework as email, and ACMA treats unsolicited commercial texts as an enforcement priority because they're so intrusive. The other common mix-up is lumping transactional and promotional messages into one bucket. "Your appointment is confirmed for Thursday" is transactional, tied to a service the person already engaged — no marketing-grade consent needed. "Get 15% off your next visit" is promotional, full stop, and that needs real, specific opt-in.

Before you send that text: a 4-question checklist

Did they opt in for marketing specifically, not just for the transaction they came for? Booking an appointment is not the same as agreeing to hear about future offers. Consent for one doesn't transfer to the other.
Is there a clear, working opt-out in the message? "Reply STOP to opt out" only counts if replying STOP actually removes them — test it, don't assume your platform handles it properly.
Do you have a record of how and when consent was given? A checkbox they ticked, a form field they filled in, a verbal opt-in you logged with a timestamp. "I'm pretty sure they'd be fine with it" is not a record.
Is this message actually transactional, or are you dressing up a promotion as a reminder? "Just reminding you it's been 6 months since your last visit... and we've got a special on!" is promotional. Be honest with yourself about which bucket it's in.

A booking-based business: Every client who'd ever made a booking got added to a general SMS list, and a promotional "we miss you, come back for 20% off" text went to the whole lot. Plenty had booked once, years ago, for something entirely different, and had never agreed to marketing texts at all. Opt-out replies rolled in within the hour, along with pointed complaints about being texted without ever signing up.

A local service business, done properly: This one keeps two separate SMS lists. Appointment reminders go to everyone with a booking, because that's transactional — no separate opt-in needed. Promotional texts about seasonal offers go only to the smaller list who ticked a genuine "yes, text me deals" box. Fewer promotional sends, zero complaints, and the people on that list actually want to be there.

How to set this up properly

Separate your SMS platform, or at least your contact tags, into two clear buckets from day one: transactional and promotional. Never let a promotional campaign pull from your full client list by default — build it from a list that only grows when someone actively opts in, whether that's a checkbox at checkout, a sign-up form, or a documented verbal yes logged immediately. Every promotional text needs a working opt-out, honoured immediately, not "within a few days." If you're unsure whether a message is transactional or promotional, write it assuming promotional — the consent bar is higher, and it's the safer default.

💡 A booking is not a marketing opt-in. If someone can't point to the exact moment they agreed to receive promotional texts from you, you don't have consent for promotional texts — you have consent for whatever transaction they actually came in for, and nothing more.

Mistakes to avoid

Exporting your entire client database into an SMS platform and treating the whole list as marketing-ready.
Assuming a number collected for a booking doubles as marketing consent, without a separate, explicit opt-in.
Sending promotional offers disguised as reminders to dodge the consent requirement — it's still promotional.
Ignoring STOP replies because "they'll probably still want to know about the sale."
Never testing your own opt-out mechanism to confirm it actually removes people.
Keeping no record of when or how consent was given.

Please note: general information, not legal advice — check current official guidance before relying on it.

Frequently asked questions

Can I text existing clients about a sale without separate opt-in?

Generally no, if it's a genuinely promotional message. An existing client relationship doesn't automatically extend to marketing consent — that needs its own, specific opt-in.

Are appointment reminders held to the same standard as promotional texts?

They sit under a lower bar because they're transactional, tied to a service the person is already engaged in. But the line blurs fast if you add promotional content into what's meant to be a plain reminder — keep reminders genuinely just reminders.

What counts as a valid opt-out?

A working, honoured "Reply STOP" mechanism is the standard approach, but requirements can shift and enforcement guidance gets updated — worth double-checking against current ACMA guidance rather than relying on what worked two years ago.

Do I need consent for a one-off missed-call text-back?

A reply directly responding to someone's own recent contact is generally treated differently to an unsolicited blast, but keep that message purely transactional rather than sneaking in a promotional offer.

Keep reading 🤍

Written by

Kate, founder of Chronically Online

I help Gold Coast and Brisbane businesses grow with branding, websites and marketing that actually works.

Work with me ✦