The rule applies specifically to alphanumeric Sender IDs, the kind that display a brand name instead of a phone number.

Starting July 1, 2026, Australia's communications regulator, the ACMA, is introducing a Sender ID Register. The rule applies specifically to alphanumeric Sender IDs, the kind that display a brand name instead of a phone number. If your program runs on long codes, no action is needed. If it doesn't, you have a registration decision to make before the deadline.

This is a practical guide to what the regulation covers, what it doesn't, and what it means for your SMS program, from compliance to long-term performance.

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What the ACMA rule requires

The rule requires businesses to verify they have legitimate ownership or authorisation to use their alphanumeric Sender ID. To complete registration, you'll need your full ABN extract or pass verification checks if you do not have an ABN, proof of Sender ID ownership or authorisation (e.g., domain alignment or trademark documentation), and a nominated authorised representative to complete the submission. In some cases, additional documentation may be required to verify identity and authorisation. 

Sender IDs that aren't registered by July 1 may be labelled "Unverified" by carriers. In some cases, they may be blocked from delivery entirely.

Registration preserves your current sending setup, but the process takes time. Delays and rejections are more common when submissions are incomplete, so starting early matters.

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Attentive’s approach: long codes, full compliance, no action needed

Attentive's Australian SMS program runs on long codes, a decision made well before this regulation came into view. That means Attentive customers are not subject to the Sender ID registration requirement and need to take no action before the July 1 deadline. Your program has been compliant under the existing framework, and it will remain so after the deadline passes.

Long codes also unlock something alphanumeric Sender IDs cannot: genuine two-way SMS. Subscribers can reply to your messages, complete in-text quizzes, share preferences, and engage in real conversations with your brand. Alphanumeric Sender IDs are one-way by design. You can send, but subscribers cannot reply.

As conversational commerce grows in Australia, the ability to listen and respond (not just broadcast) is becoming a meaningful differentiator. But the case for long codes goes deeper than what they enable today. We've long recognized that alphanumeric Sender IDs carry real fraud risk: the infrastructure for verifying ownership simply wasn't there, and bad actors could impersonate a brand's Sender ID with minimal friction. That's why we declined to support alphanumeric Sender IDs, both in Australia and internationally, years before regulators acted.

The ACMA's Register exists to solve exactly that problem. Introduced as part of the Australian Government's Fighting Scams campaign, it ensures every Sender ID is verified and traceable. Our commitment to brand protection led us here long before it became a regulatory requirement—and it's the same commitment that shapes how we build everything else on our platform.

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What you need to know to stay compliant

Your compliance path depends on how your SMS program is set up.

If you're sending with an alphanumeric Sender ID, registration is required before July 1. Starting early reduces the risk of delays or rejections.

If you're sending with long codes, no registration is required. Your program is compliant under the existing framework.

If you're unsure which applies to you, the simplest check is whether your messages arrive showing a brand name or a phone number. A brand name typically indicates an alphanumeric Sender ID, though RCS messages can also display brand names and operate under a separate set of rules. A phone number means you're on long codes or a shortcode. If you're still unsure, confirm with your current provider.

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What makes a strong SMS program in Australia

Beyond compliance, this is a good moment to evaluate whether your SMS infrastructure is set up to perform. The fundamentals of a high-performing program are list growth, deliverability, and the ability to build real relationships with subscribers. Here’s where the meaningful differences between approaches show up.

Sign-up experience and list growth

How subscribers join your program has a direct impact on both the size and quality of your list. Attentive’s patented Two-Tap™ mobile technology is a sign up method that takes just two taps with no typing required, driving more than 2x more subscribers compared to other sign-up approaches.

The flow works by triggering a pre-filled text message that subscribers simply tap to send. The resulting double opt-in has supported brands in compliance proceedings, and the sign-up process is designed to establish clear, documented subscriber consent.

iOS 26 and inbox visibility

Apple’s iOS 26 introduced filtering that routes messages from unknown senders into a separate inbox where notifications are silenced. Subscribers who have Unknown Sender filtering on and sign up through manual phone entry or Reply Y flows end up in that inbox. Messages that reach the Unknown Sender inbox can see click-through rates up to 40% lower.

Subscribers who join through Two-Tap™ are automatically classified as Known Senders on iOS, which means their messages land in the main inbox where they’re seen. It’s a performance difference that compounds as your list grows.

Compliance tools built into how you operate

The ACMA rule is one compliance moment, but running a healthy SMS program means building compliance into day-to-day operations: how subscribers opt in, how opt-outs are handled, and how your infrastructure maintains audit trails.

Attentive’s platform includes sign-up templates designed to obtain express consent, and detailed audit records. The platform was built with compliance in mind, and offers compliance tools and guardrails throughout.

Weighing your options

If you’re currently on an alphanumeric Sender ID, you have two paths to consider before July 1.

Registration keeps your current setup intact. The trade-off is that it preserves a one-way sending infrastructure at a moment when two-way conversations are becoming more valuable.

Moving to long codes removes the registration requirement and opens up two-way messaging, with the added benefit of better positioning for iOS 26 inbox delivery. If you're evaluating a switch, Attentive handles the technical setup, message deliverability, and compliance tooling so your team can stay focused on driving results.

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The opportunity inside the deadline

Compliance deadlines tend to focus attention on what’s required. The brands that get the most out of moments like this are the ones who look a little further: at what their program is capable of, not just what it needs to avoid.

The Australian SMS market is growing. Subscribers are more receptive to brands that communicate relevantly and conversationally. The infrastructure decisions you make now will shape your results for years. 

Building something worth subscribing to is the goal. The compliance question is just the starting point.

Want to talk through what the ACMA rule means for your specific setup? Attentive’s team is here to help, whether you’re an existing customer or evaluating your options.

Sources

2x+ more subscribers via Two-Tap™ vs. other sign-up methods: Attentive internal data

40% lower click-through rates when messages land in iOS Unknown Sender inbox: Attentive internal data

Zero compliance judgements against Attentive clients over 10+ years: Attentive record

ACMA Sender ID Register requirements: acma.gov.au/industry-rules-sms-sender-id-register

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This post is for informational purposes only and does not constitute legal advice. Please consult your legal counsel regarding your specific compliance obligations.