SMS opt out in Australia: what the rules require
How SMS opt-outs work under Australia's Spam Act: what recipients can do, what businesses must honour within 5 working days, and how to set it up properly.
If you want to stop commercial texts from an Australian business, replying STOP (or following the unsubscribe instruction in the message) is the usual route, and the sender must honour it. If you are the business sending those texts, the law is just as clear: every commercial message needs a free, working way to opt out, and you must act on a request within 5 working days. This guide covers both sides, with the detail that trips businesses up in practice.
TL;DR
- Under the Spam Act 2003, commercial SMS must carry a clear, free unsubscribe option, and the sender must action opt-outs within 5 working days.
- STOP is the common convention, but the law asks for a clear instruction that works. Examples such as replying NO or using a web link are accepted.
- Automated sequences, welcome journeys and outsourced campaigns are not exempt. The business stays responsible.
- If a sender ignores your opt-out, you can report it to the ACMA.
- Do not reply to scam texts. Report them and delete them.
Table of Contents
- What the law says about opting out of SMS
- If you are the recipient: how to stop business texts
- If you are the sender: what a compliant opt-out looks like
- Setting up opt-out handling that does not leak
- Mistakes we see most often
- Our perspective
- How an AI platform can take the manual work out
- Penalties and complaints
- FAQ
- Sources
What the law says about opting out of SMS
In Australia, text messages that offer, advertise or promote a business, good or service are “commercial electronic messages”. The Spam Act 2003 covers SMS, MMS and instant messages as well as email. The regulator is the Australian Communications and Media Authority (ACMA).
The Act rests on three requirements, and opt-out is one of them:
- Consent. The sender needs express or inferred consent before sending.
- Identification. The message must accurately identify the sender and include valid contact details.
- Unsubscribe. The message must include a clear, easy-to-use way to opt out.
The third requirement is what this article is about. It protects you as a recipient, and it shapes how a business must build its SMS program.
If you are the recipient: how to stop business texts
Use the instruction in the message
A legitimate marketing text should tell you how to opt out. Typical wording looks like “Reply STOP to opt out” or “Unsub: reply NO”. The second is actually the example business.gov.au gives for SMS. So STOP is a convention, not a legal keyword. Whatever instruction the message gives is the one to follow, and a link to a website is also acceptable.
Two points about cost and speed:
- The business cannot charge you a fee for opting out, although standard text rates from your plan may apply to a reply.
- The sender must process the request within 5 working days. A text arriving a day or two after you opt out is not necessarily a breach, but one arriving weeks later probably is.
Keep a record
Take a screenshot of the original message and of your reply, with the date and time. If you have to complain, this evidence is what the regulator will want.
When the texts keep coming
If a business keeps messaging you after the 5 working days, you can report it to the ACMA, which can investigate and take action such as fining a business. It is worth contacting the business directly first, mainly to create a clear paper trail.
Texts that are not from legitimate businesses
The opt-out system assumes a real sender who follows the rules. A scammer will not. If a message is clearly a scam, replying STOP only confirms that your number is active. Do not click links or reply. Report it through the ACMA’s spam reporting guidance and delete it.
The same applies to a message that is borderline: from a business you have never dealt with, in a style that looks off. Contact the organisation through its official website or phone number rather than through the text.
If you are the sender: what a compliant opt-out looks like
Most of the Australian ranking guides address marketers, and with good reason. The ACMA’s own research found a notable knowledge gap among small and medium businesses, with many wrongly believing the unsubscribe rules did not apply to them. They do.
The checklist
| Requirement | What it means in practice |
|---|---|
| Clear and easy | A short instruction in every commercial message. No logins, no multi-step forms. |
| Free | You cannot charge for the opt-out. Standard carrier rates for a reply may apply. |
| Working for 30 days | The unsubscribe facility must stay functional for at least 30 days after the message is sent. |
| Actioned fast | No later than 5 working days after the request. |
| Sender identified | Your business name and valid contact details are accurate in each message. |
Keep the instruction unambiguous
Pick one opt-out word and state it plainly. Many businesses use STOP because customers expect it. Consider also accepting common variants such as UNSUBSCRIBE, END, CANCEL and QUIT, plus a clear reading of replies like “please stop texting me”. Those extra keywords are good practice rather than a legal list, but a customer who writes in full sentences should not be left receiving messages because a system only matched one exact word.
Do not entice people back
The ACMA has flagged that some businesses may be breaching spam laws by sending messages to entice consumers who have withdrawn consent. A “we miss you, come back for 10% off” text sent to someone who has opted out is exactly this kind of problem. Once someone opts out of marketing, suppress their number from every promotional list and campaign.
Factual does not mean exempt
A message can still be commercial even if most of it is factual. An appointment reminder with a line promoting an upgrade, or an account notice with a sales offer tacked on, can fall within the rules. If a text has a promotional purpose, treat it as marketing and include the opt-out. We cover the practical side of reminders in our guide to SMS appointment reminders for Australian businesses.
Automated sequences are covered too
The ACMA has made clear that “welcome journeys” and other automated SMS sequences are not exempt from the Spam Act and need fully functional unsubscribe mechanisms. The same goes for drip follow-ups, cart reminders and lead nurture. A marketing automation checklist is a sensible place to confirm each automated step has its own opt-out, and that an opt-out in one step halts all the others.
You cannot outsource the responsibility
If an agency, a call centre or a software vendor sends on your behalf, you are still accountable. The ACMA states that businesses remain responsible for spam and telemarketing rule compliance even when using third-party marketers. Ask each provider how opt-outs are captured, how fast they flow back to your master list, and who holds the suppression record.
Setting up opt-out handling that does not leak
The biggest failure is rarely the wording of the message. It is the gap between a customer replying STOP and every system that sends them messages actually knowing about it.
The ACMA’s SME research found that where opt-outs were not handled automatically, 88% of SMS-sending SMEs said they removed customers within 5 business days, and that SMS opt-outs were more often actioned manually than email ones. Manual handling works at low volume. It fails when a team is busy, a person is away, or a second platform keeps its own list.
A workable setup looks like this:
- One suppression list. Every channel and every tool that can send a text checks the same list before sending.
- Automatic capture. An inbound opt-out reply is flagged and applied immediately, not queued for someone to read.
- Confirmation message. A single reply such as “You have been unsubscribed and will not receive further marketing texts” is a courtesy. Keep it free of any promotion.
- Consent record. Store when and how each person consented, the wording they saw and when they withdrew. The ACMA recommends that express consent be gathered through clear terms that explain how consent can be withdrawn.
- Regular testing. Opt out from a test number every month and confirm that nothing arrives afterwards.
- Respect the speed limit. Aim for same-day removal. Five working days is the legal ceiling, not a target.
For templates and the wording of consent requests, see our guide to SMS consent management in Australia.
Sender IDs and opt-out
Branded sender IDs are a separate obligation but sit in the same compliance picture. From 1 July 2026, texts sent with an organisation’s name at the top need that sender ID registered. A registered name makes your message more recognisable, which also reduces the chance a confused recipient reports it as spam instead of simply opting out. Our post on outbound SMS campaign compliance and sender ID risks covers the practical consequences.
Opt-out is not the same as the Do Not Call Register
Phone calls and texts follow overlapping but different rules. A Do Not Call Register listing relates to telemarketing calls, while a text opt-out is handled with the sender. If you run both voice and SMS, read our summary of Do Not Call rules in Australia so the two lists are not confused.
Mistakes we see most often
- Opt-out only in the first message. Every commercial message needs it, including follow-ups.
- A link that needs a login. If an unsubscribe page asks someone to remember a password, it is not easy to use.
- Opt-out applied to one list only. Someone opts out of promotions, then gets a message from a different campaign tool.
- Reply keywords that only work in capitals, or only one word. Real customers type naturally.
- Re-adding people on a data import. A fresh CSV from a trade show or a CRM merge can silently re-enrol people who opted out. Always check imports against the suppression list.
- Assuming the agency handles it. See above: you remain responsible.
- Treating a collections or sales text as “just information”. If it promotes or offers something, it is likely commercial.
Our perspective
We build conversational AI for Australian businesses, and SMS opt-out is where compliance meets software design. Our view is simple: an opt-out should not depend on a person noticing a reply. A customer who writes “stop” at 9pm on a Sunday should be removed from every channel before the next scheduled message goes out.
That is why we treat opt-out as a shared state across SMS, voice, email and live chat, held in the same CRM record and hosted on Australian infrastructure. When one channel learns that a customer has withdrawn consent, the other channels should know too. It is also why we believe automation and compliance are not in tension: a system that always checks the suppression list before it sends is more reliable than a manual process in a busy week.
For regulated sectors such as healthcare, finance and collections, we add one more principle: keep the record of consent and withdrawal under your own control, within Australia. If an auditor or the regulator asks for evidence, you should be able to produce it without chasing an overseas vendor.
— Sowrabh
How an AI platform can take the manual work out
If your team handles opt-outs by reading replies and editing spreadsheets, the risk is not bad intent. It is a Tuesday when two people are off sick. Our SMS AI Agents and multichannel platform recognise natural-language opt-out replies, update the customer’s record, and stop scheduled follow-ups across channels. It integrates with your CRM, and the data stays hosted in Australia. Pricing is not published, so the quickest way to see whether it fits your volumes and sector is to ask for a demo.
Penalties and complaints
The ACMA investigates spam complaints and can penalise businesses that fail to comply with the Spam Act. Reports typically come from the people you message, which is why a broken opt-out is more dangerous than it looks: it creates complainants. For current enforcement outcomes and penalty amounts, check the ACMA’s own pages rather than relying on a figure in a third-party summary.
The practical protection is evidence. Keep message logs, consent records, the opt-out timestamp and the time of the last message sent. If a complaint arrives, you can show what happened.
FAQ
Do I have to reply STOP to opt out of SMS in Australia?
Not necessarily. STOP is a widely used convention, but the law requires a clear, easy way to opt out, and the sender chooses the method. Follow the instruction in the message, whether that is replying with a word like NO or using a link. The sender cannot charge you for opting out.
How long does a business have to stop texting me after I opt out?
A business must action your request no later than 5 working days after you make it. Many systems do it immediately. If texts continue after that, keep screenshots and report the sender to the ACMA.
Can I opt out of scam or spam texts?
Not in the same way. Replying to a scammer can confirm your number is active. Do not click links or respond. Delete the message and report it to the ACMA.
Does a business need consent before texting me at all?
Yes. A business needs express or inferred consent before it sends commercial messages. Opting out then withdraws that consent, and the business should not send further marketing texts or try to entice you back.
Sources
- Promoting your business by email or text messages (business.gov.au)
- Avoid sending spam (ACMA)
- Small and medium-sized businesses: marketing messages and unsubscribe rules (ACMA research report)
- Telemarketing and e-marketing: common issues and mistakes (ACMA)
- Consent expectations for businesses using direct marketing (ACMA)
- Dealing with spam (ACMA)
- SMS Sender ID Register (ACMA)
