The SMS Sender ID Register: most businesses don't need to do a thing
The ACMA SMS Sender ID Register has been in force since 1 July 2026, and it only affects texts that show a brand name as the sender (like “Coax”). If your texts come from a phone number, ACMA says you don't need to do anything. Coax sends every message from a long code - a real phone number, not a brand name - so Coax customers aren't affected at all. Nothing to register, now or ever.
Last updated . Read ACMA's current guidance.
What Changed On 1 July 2026
A new register for brand-name texts. Aimed at scammers, not you.
The Australian Communications and Media Authority (ACMA) launched the SMS Sender ID Register on 1 July 2026 to shut down sender-ID spoofing, where scammers impersonate trusted brands. Here's what it actually does.
It only touches brand-name senders
The register covers alphanumeric sender IDs - the brand-name headers that show at the top of a text, like "Coax", "ATO" or "AusPost". Nothing else is affected.
Unregistered names get over-stamped
Send under a brand name that isn't registered and networks over-stamp it with the word "Unverified", bundling every unverified-sender message into one thread - right next to genuine scam texts.
It's a label, not a block
ACMA doesn't block or delete your messages. The change is a carrier label and a grouped thread, designed to shut down sender-ID spoofing where scammers impersonate trusted brands. Registering proves the name is really yours.
Do You Even Need To Do Anything?
Most businesses don't. Here's the test.
The register only touches alphanumeric sender IDs. If you send from a numeric number - a regular +614 mobile or a long code - the register doesn't apply to you. ACMA's own guidance is blunt: “If you don't use a sender ID, or you send messages from a phone number, you don't need to do anything.”
You send from a brand name (e.g. "Coax")
Affected - register your sender ID so your header arrives verified, not flagged.
You send from a phone number / long code
Not affected - nothing to register, and your texts keep working as normal. Numeric numbers are never labelled "Unverified".
Not sure which you use?
That's the most common answer, and it takes us about two minutes to check for you. We'd rather tell you you're already fine than sell you a fix you don't need.
The Easy, Compliant Option
Why a phone number keeps you clear of the register
A sender ID has to be 2 to 11 characters and must not consist only of numbers - so a numeric long code can't be registered as a sender ID, and doesn't need to be. Sending from a number keeps you out of the register entirely.
There's a practical upside too. A number is two-way: customers can text you back, and “Reply STOP” works for unsubscribing. Alphanumeric brand tags generally can't receive replies, so a “reply to unsubscribe” instruction on a brand header doesn't actually meet your obligations - you'd need a separate opt-out.
The Simplest Path
Compliant, two-way, nothing to register.
For a lot of Australian small businesses, trades and retailers, a clean numeric long code is the simplest path. It stays out of the register, lets customers reply, and handles opt-outs the way the law expects.
Coax sets up whichever path you need - numeric long code or registered brand sender ID - so you're covered without the guesswork.
If You Send Under A Brand Name
You can't register with ACMA yourself. With Coax you don't need to.
There's no public portal where a business lodges its own sender ID. Registration can only be submitted by an ACMA-approved participating telco or eligible messaging service provider (EMSP), on your behalf, through approved channels - it's not something you do “directly with ACMA”.
Coax sidesteps that entirely. Every Coax message sends from a long code - a dedicated Australian phone number, not a brand name. So Coax customers are not affected: there's no header to register, your texts are never labelled “Unverified”, and customers can reply straight back.
The Coax Approach
Send from a long code. Nothing to register.
Coax sends from a real phone number (for example, +61 4XX XXX XXX). A number can't be an alphanumeric sender ID, so it falls outside the register completely - no registration step, no “Unverified” label.
As a bonus, a number is two-way: customers can text back, and “Reply STOP” works for opt-outs. Compliant by design, not by paperwork.
The Register Is The Floor, Not The Finish Line
Registering isn't a free pass on the rest of Australian SMS law.
Registering a sender ID (or sending from a number) is not the whole picture. These obligations still apply on 1 July and beyond - we treat compliance as the on-ramp, not the product.
Spam Act 2003
You need consent to message, you must identify yourself as the sender, and you must honour an unsubscribe within 5 working days.
The C661 Scam SMS code
The industry rules aimed at blocking scam and spoofed messages apply in parallel, on 1 July and beyond.
A working opt-out
"Reply STOP" works on a numeric long code, but alphanumeric brand tags generally can't receive replies - so "reply to unsubscribe" on a brand header isn't compliant. You need a genuine opt-out mechanism either way.
Coax builds these in by default.
Consent tracking, clear sender identification, and unsubscribe handling are baked into how messages send. Compliance isn't a checkbox you have to remember - it's how the platform works.
Beyond The Deadline
Getting SMS sorted for 1 July is just the on-ramp.
Coax is an Australian, AI-first customer communication platform. The real win is messaging that books jobs and closes sales - the 1 July change is just handled inside your account.
Multi-channel in one inbox
SMS, voice and social together, so leads don't slip through the cracks.
An AI sales & service assistant
Replies fast, qualifies enquiries and books the job while the lead is still hot.
Reviews, bookings & payments
Wired into the same conversation, not bolted on as separate tools.
Built for AU SMBs
Trades, retailers and dealerships - a modern alternative to Podium, run from here.
Still Have Questions?
Not sure if 1 July affects you? Let's find out in two minutes.
Tell us how you send your texts today and we'll give you a straight answer about whether 1 July touches you at all. Coax itself sends from a long code, so Coax customers aren't affected, with nothing to register. If you send under a brand name today and want to talk through your options, we'll walk you through it - no upsell.
Australian team, plain answers, no scare tactics. Or call us on 1300 370 463.
FAQ
Common questions about the SMS Sender ID Register.
What is the ACMA SMS Sender ID Register?
It's an Australian register, in force since 1 July 2026, for alphanumeric SMS sender IDs - the brand-name headers like “Coax” or “AusPost” that appear at the top of a text. Registering proves the name belongs to your business so messages aren't flagged as potentially fraudulent. It's run by the Australian Communications and Media Authority (ACMA) to combat sender-ID spoofing by scammers.
What happens if I do not register my sender ID?
From 1 July 2026, SMS sent under an unregistered alphanumeric sender ID gets over-stamped by carriers with the word “Unverified” and grouped into a single thread on the recipient's phone alongside other unverified senders. ACMA doesn't block or delete the messages - but to customers your legitimate texts start looking like scams, which hurts open rates and trust.
I send SMS from a phone number, not a brand name. Do I need to register?
No. The register only covers alphanumeric sender IDs. ACMA states: “If you don't use a sender ID, or you send messages from a phone number, you don't need to do anything.” Numeric numbers and long codes aren't covered and are not labelled “Unverified”. If you're not sure which type you use, Coax can check it for you in a couple of minutes.
Can I register my SMS sender ID directly with ACMA?
No. There's no DIY portal - registrations can only be lodged by an ACMA-approved participating telco or eligible messaging service provider (EMSP) on your behalf, through approved channels. Coax takes a simpler route - every Coax message sends from a long code (a real phone number), so Coax customers aren't affected and have nothing to register.
Does Coax use a sender ID? Do I need to register one?
No. Coax sends every message from a long code - a dedicated Australian phone number (for example, +61 4XX XXX XXX), not an alphanumeric brand name. That keeps Coax and its customers outside the register: there's nothing to register, your texts are never labelled “Unverified”, and customers can reply directly, so “Reply STOP” works for opt-outs.
Can a phone number be registered as a sender ID?
No. A sender ID must be 2 to 11 characters and must not consist only of numbers, so a numeric long code can't be registered as a sender ID. That's also why number-senders have nothing to do for 1 July - the register doesn't apply to them at all.
Does registering my sender ID mean I'm fully SMS-compliant?
Not on its own. The register sits alongside existing obligations that still apply, including the Spam Act 2003 (consent, sender identification, and honouring unsubscribes within 5 working days) and the C661 Scam SMS code. Note that “Reply STOP” works on a numeric long code, but alphanumeric brand tags generally can't receive replies, so a “reply to unsubscribe” instruction on a brand header isn't compliant. Coax builds consent, sender ID and opt-out handling into how messages send.
See what else Coax has to offer here →