The SMS sender ID register

A sender ID is an alphanumeric message header that appears at the top of SMS/MMS messages. It tells you who the message is from, for example, ‘ATO, ‘CBA’, ‘myGov’. It can be made up of letters, numbers and/or symbols, but cannot consist only of numbers for the purposes of the register. 

The register will protect consumers that receive SMS/MMS messages, and the entities that send those messages, by disrupting impersonation scams. These are where scammers send SMS/MMS with sender IDs that imitate well-known brands, such as banks and government agencies, to deceive victims and steal their money or personal information. 

In April 2023, the government announced that the ACMA will implement a SMS sender ID register. The ACMA launched a pilot register in December 2023.

The Minister for Communications directed the ACMA to make rules for the register and for the register to begin by no later than 15 December 2025. 

The registration model will be mandatory in Australia. This means that entities that use sender IDs to send SMS/MMS messages to Australian mobile numbers will have to register any sender IDs they intend to use. Messages sent with unregistered sender IDs will be disrupted.

Under our proposed model, if messages are sent with unregistered sender IDs, the sender IDs for those messages will be replaced with ‘Likely SCAM’ (or similar wording). 

This means the intended recipient will receive the message, but the message header of ‘Likely SCAM’ will alert the recipients that the message may be a scam. Alternatively, messages sent with unregistered sender IDs could be blocked, meaning the intended recipient will not receive the message.

Australian telcos must be approved by the ACMA to participate in the register. Non-participating telcos will not be permitted to send sender ID messages. 

Registration of sender IDs means that only legitimate entities can send messages with sender IDs, and consumers can be confident that messages they receive with sender IDs are not scams.

The register will not impact SMS messages that are sent directly from one person to another person from personal mobile devices. 

We are consulting on whether arrangements could be implemented to allow international entities to participate in the register, without compromising the security and effectiveness of the register.

Registration of sender IDs will be mandatory. If an entity sends SMS/MMS messages with an unregistered sender ID after 15 December 2025, we propose that those messages will be labelled as ‘Likely SCAM’ (or similar wording). 

Registering sender IDs will benefit entities by addressing common harms associated with SMS impersonation scams, including:

• people may stop trusting legitimate messages from entities, and/or form a negative view of the entity that the message falsely claims to come from
• people that have fallen victim to an impersonation scam may expect the entity that is being impersonated to reimburse them for any money they’ve lost or take other action to resolve the problem.

Only entities (that is, businesses and agencies) that have applied to the ACMA and been approved can register sender IDs. We are consulting on the proposed operation of the register, including the application process. We are proposing that to be approved:

• an entity must be on the Australian Business Register
• the person making the application must be authorised by the entity and pass an ID check
• the sender ID must be directly associated with the entity.

The aim of this process is to prevent scammers accessing the register.

Yes, you need to register your sender IDs before 15 December 2025 to avoid the sender ID for messages you send being disrupted, for example labelled as ‘Likely SCAM’ (or similar wording).

We are consulting on the proposed implementation and operation of the register. We are proposing that entities will be able to start applying to register sender IDs by contacting their telco starting from around October 2025.

We are consulting on whether to limit the number of sender IDs an entity can register. If an entity only uses only one or 2 sender IDs, it may make it easier for consumers to identify who the message is from, and entities can provide clear guidance to their customers about which messages they can trust. For example: ‘the ACMA will only send you messages using the ‘ACMA’ sender ID'.’ 

We are proposing that applications to register will open around October 2025. The register will be operational by 15 December 2025. After 15 December 2025, SMS/MMS messages sent with unregistered sender IDs will be disrupted, for example, labelled as ‘Likely SCAM’ (or similar wording).

If you do not register your sender ID by 15 December 2025, your SMS/MMS messages will be disrupted, for example labelled as ‘Likely SCAM’ (or similar wording). 

We are consulting on sender ID criteria. We propose that a sender ID: 

1. Must be at least 3 and no more than 11 characters long.
2. Must, with limited exceptions, include letters, or a combination of letters (A-Z), numbers (0-9) and symbols, but cannot consist of only numbers. Sender IDs will be case-insensitive (for example, ‘ABC’ is treated the same as ‘abc’). 
3. Must start with a letter, with limited exceptions.
4. Must not contain non-Latin characters. 
5. Must not contain a space or underscore at the beginning or end. 
6. The only symbols permitted are: + - _ &

Yes, we are proposing that more than one approved entity may register the same sender ID, if they can prove the sender ID is directly associated with that entity’s name or brand name. For example, if the ACMA attempted to register ‘ACMA-alert’, the sender ID would be accepted. However, if the ACMA attempted to register ‘Telco alert’, it would not be accepted unless the ACMA could provide evidence that ‘Telco alert’ is an ACMA brand or business name.

Access the consultation paper and other related information about making a submission. 

We will use feedback to our consultation to progress the register and register rules. The register will begin by 15 December 2025.