ABNs explained

An ABN is a unique 11-digit number that identifies your business to the government, other businesses and the public. It doesn't replace your tax file number.

You can use an ABN to:

  • verify your business to others when ordering and invoicing
  • avoid pay as you go (PAYG) tax on payments you get
  • claim goods and services tax (GST) credits
  • claim energy grants credits
  • get an Australian (.au) domain name.

It’s free to register for an ABN through the Australian Government’s Business Registration Service.

Find out if you need an ABN

Not everyone needs an ABN. To get one you need to be running a business or other enterprise.

Find out if you’re entitled to an ABN on the Australian Business Register (ABR) website. The Australian Taxation Office (ATO) manages the ABR.

Before you register for an ABN, make sure you’ve got all the information needed about your business.

Register for an ABN

You can apply for an ABN and other business registrations through the Business Registration Service. Before you register, have these things ready:

  • your business structure
  • proof of identity
  • details of your business activities and associates.
Register for an ABN

If you give all the information needed, you'll find out about your ABN as soon as you’ve completed your online application. 

You’ll get:

  • your ABN, if your registration was successful
  • a refusal number if it’s unsuccessful. You’ll also get a letter within 14 days with a reason
  • a reference number if your application needs further review.

Reviews can take 20 business days and the ATO may contact you for more information.

You can register a business name and ABN together if you use the Business Registration Service. Or you can use the Business Registration Service to register your business name later.

Make sure you understand the difference between your ABN and your registered business name. 

Find out more about registering your business name.

You can apply for an ABN and ACN using the same form on the Business Registration Service.

You have 28 days after becoming aware of a change to update your details. The ABR has more information on updating your ABN information.

If you change your business structure, you may need to apply for a new ABN.

When your business changes, you may also need to update your business name details with the Australian Securities and Investments Commission (ASIC).

Use ABN Lookup to find publicly available registered ABN information. For example, you can check:

  • that your ABN details are up to date
  • a supplier’s details.

You'll need to cancel your ABN if you:

You'll need to cancel your ABN when changing from a:

Cancel your ABN on the ABR website.

You can contact the ABR if you need more information about:

  • how your application for an ABN is progressing
  • updating your ABN.

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