Whether you run a business in Australia or are setting one up from overseas, it helps to understand two numbers you will see everywhere: the ABN and the ACN. This article explains what each one is, how to get them, and how to keep the details up to date.
In short, an ABN identifies a business of any kind, while an ACN identifies a registered company.
What is an ABN?
ABN stands for Australian Business Number. It is a unique 11-digit number held on the Australian Business Register (ABR), which the Australian Taxation Office (ATO) runs. It identifies your business to the government and the community. It is not the same as a Tax File Number (TFN) and cannot replace one.
You can look up public ABN details on ABN Lookup. Most businesses quote their ABN on invoices, and you must have an ABN to register for GST.
If you supply goods or services to a business without quoting an ABN, that business generally has to withhold 47% of the payment and send it to the ATO. The ATO explains the rules on withholding when no ABN is quoted.
You can apply for an ABN free of charge on the ABR website.
How do I update my ABN details?
You must tell the ABR about changes to your ABN details within 28 days. These include:
- your GST registration status
- address information
- business owner details
- contact information.
Some details are not updated through the ABR:
- business names
- legal names of sole traders and individuals, which the ATO updates
- legal names of Australian companies, which ASIC updates.
You don't need to tell the ABR about these name changes. The ATO and ASIC update the ABR for you.
You can make most updates online through the ABR website. If you change your business structure, you may need a new ABN.
How long does it take to get an ABN?
If you provide all the information the application asks for, you will usually receive your ABN online as soon as you finish applying.
If information is missing or can't be verified, your application is processed manually, which can take up to 28 days, and you may be asked for more information. If your application is refused, you will receive a letter explaining why and what you can do next.
What is an ACN?
Every company registered under the Corporations Act 2001 receives an Australian Company Number (ACN) from the Australian Securities and Investments Commission (ASIC). It is a unique 9-digit number, usually shown as three groups of three digits, and it appears on your company's Certificate of Registration.
Your ACN, registered office, officeholders and shareholders are on the public record and can be found through ASIC's registers.
A company's ACN must appear on its public documents, including:
- documents lodged with ASIC
- statements of account, including invoices
- receipts that are not machine-produced
- orders for goods and services
- business letterheads
- official company notices
- cheques, promissory notes and bills of exchange
- written advertisements making a specific offer.
The company's name and ACN must appear on the first page of these documents, clearly and legibly. See ASIC: Australian Company Number.
How do I update my company details?
Company details are updated with ASIC, not through the ACN itself. You must tell ASIC about changes to your company details within 28 days, and changes are lodged online. Your accountant or ASIC registered agent can lodge them for you.
ABN and ACN in summary
An ABN is an 11-digit number for any business, held by the ABR. An ACN is a 9-digit number for registered companies only, issued by ASIC. A company that carries on a business usually has both, and a company's ABN is normally its ACN with two extra digits at the front.
Overseas companies that register in Australia receive a different number, the ARBN. Our article on the differences between Australian subsidiaries and registered foreign companies explains it.
For help with your company's ASIC obligations, see our ASIC registered agent service, call +61 7 5600 9777 or send us a message.
