Applicable identifiers (ABN, ACN, and ARBN) for a subsidiary and branch in Australia
When expanding into Australia, one of the first steps international businesses must take is to decide how they want to operate locally, as a subsidiary company or as a branch of a foreign entity. Each pathway comes with unique compliance obligations and, importantly, requires different business identifiers such as an Australian Business Number (ABN), Australian Company Number (ACN), and Australian Registered Body Number (ARBN).
By Ro Elvinia
Understanding these identifiers is crucial. They not only determine how your entity is registered with the Australian Business Register (ABR) and the Australian Securities and Investments Commission (ASIC), but also how your business is recognised by the Australian Taxation Office (ATO), customers, and trading partners.
What is an ABN
The ABN is an 11-digit number that allows you to register for Goods and Services Tax (GST), interact with the ATO, and be identified by customers, suppliers, and other stakeholders. Whether your entity is a subsidiary or a branch, you will need an ABN in order to conduct business in Australia.
What is an ACN
An ACN is a nine-digit number issued by the ASIC to every company incorporated in Australia. A subsidiary company must have an ACN, and this number is required to be displayed on various documents.
What is an ARBN
The ARBN is also a nine-digit number but is reserved for entities that are not incorporated in Australia, such as foreign companies establishing a branch. Like the ACN, it must appear on all relevant documents, and it is the key identifier used by ASIC to recognise and regulate foreign bodies operating in the country.
Why the identifiers matter
Choosing between a subsidiary and a branch determines which identifiers your business will require and, more importantly, how your entity will be recognised in Australia. Subsidiaries are issued both an ACN and an ABN, which together confirm their status as Australian-incorporated companies. Branches, on the other hand, are issued an ARBN and are allowed to apply for an ABN, which signal that they remain foreign entities operating within Australia under the oversight of their parent companies.
The implications extend well beyond registration. These identifiers shape how your business is regulated, taxed, and perceived in the marketplace. From a compliance perspective, regulators require them to be included on a wide range of public-facing and legal documents to ensure transparency. Failure to display them correctly can result in penalties, delays in payment, or loss of trust with suppliers and customers.
Depending on whether you are using an ABN, ACN, or ARBN, the rules differ slightly.
ABN
Any entity carrying on business in Australia is required to show its ABN in several key places, including:
- Invoices and receipts issued to customers, particularly where GST applies
- The company’s common seal, if one has been adopted for official use
- Cheques and other negotiable instruments used in transactions
- Public documents and business communications that identify the organisation
- Government forms and documents submitted to ASIC or other agencies
ACN
For companies incorporated in Australia, the ACN is a mandatory marker of compliance and must be shown on a wide range of official and commercial documents. Specifically, the ACN must be displayed in the following situations:
- On letterheads and other official stationery
- On all documents filed with ASIC
- On invoices, statements of account, and purchase orders issued to customers or suppliers
- On receipts that are manually written (machine-generated receipts are exempt)
- On the company’s common seal, if one has been adopted
- On company notices and any other formal communications from the business
- On cheques, promissory notes, and bills of exchange used in financial transactions
- On advertisements that contain a specific public offer
There are several exceptions where displaying the ACN is unnecessary. These include:
- Credit cards and vouchers
- Packaging and product labels
- Advertisements that do not contain a specific offer
- Receipts that are automatically produced by a machine
- Business cards and compliment slips, as these are informal in nature
ARBN
Once a branch company is registered, the Corporations Act requires that this number be displayed in specific situations, including:
- On all public documents produced by the branch in Australia
- On contracts and formal agreements signed in the country
- On negotiable instruments, such as cheques and promissory notes, that are executed within Australia
Displaying the ARBN makes it clear that the entity is a registered foreign company operating locally, rather than an Australian-incorporated subsidiary. This transparency helps regulators, trading partners, and customers identify the business correctly.
How ABN Australia can help
Expanding into Australia starts with choosing the right structure and right partner. At ABN Australia, we help international businesses navigate this process by assisting with both company formation and branch establishment. Our role is to simplify the registration and compliance steps so you can focus on building your presence and connecting with the local market.
If you’re considering expansion, we’re here to guide you through the details and make the transition as straightforward as possible. Contact ABN Australia today to make your expansion process seamless.
Published: 05th Sept 2025 | Last updated: 05th Sept 2025
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