An Australian business number (ABN) is an unique 11-digit number used to identify businesses in Australia.
Who needs an ABN
Registering for an ABN is not compulsory for your business, but you must have one to register for goods and services tax (GST).
If you don't, other businesses can withhold 46.5% from any payment to you for tax purposes.
You must know your business structure before you apply. Find out what else you need to apply on the Australian Government's Australian Business Register website.
Check your ABN
You can check the status of your ABN using the Australian Government's ABN Lookup.
Register for GST
You can't register for GST unless you have an ABN.
Check if your business must be registered for GST on the Australian Tax Office website.
Register for GST at the same time as applying for an ABN using the Australian Government's Business Registration Service.