ABN Registration Guide — How to Get an Australian Business Number
An Australian Business Number (ABN) is an 11-digit identifier required for most business activities including invoicing, GST registration, and government dealings. Registration is free through the Australian Business Register (ABR) and can be completed online in minutes for sole traders, or may require additional documentation for companies and trusts. ABN holders must update their details within 28 days of any change.
Overview
An Australian Business Number (ABN) is an 11-digit identifier required for most business activities including invoicing, GST registration, and government dealings. Registration is free through the Australian Business Register (ABR) and can be completed online in minutes for sole traders, or may require additional documentation for companies and trusts. ABN holders must update their details within 28 days of any change.
Key Facts
- ABN registration is free — do not pay third-party services that charge for it
- Sole traders can register instantly online via abr.gov.au with their TFN
- Companies need an ACN (from ASIC) before applying for an ABN
- ABNs must be cancelled if you stop carrying on a business — the ATO audits inactive ABNs
- Without an ABN, payers must withhold 47% from payments under the 'no ABN withholding' rule
What You Need to Know
This guide covers the essential compliance requirements that Australian employers need to understand. Non-compliance can result in significant penalties, ATO audits, and reputational damage.
We recommend using purpose-built software that automates compliance reporting. The right software will handle rate changes, deadline reminders, and lodgement with the relevant authorities.
Official Resources
For the latest official requirements, refer to these government resources:
- Australian Business Register — Register for an ABN online for free through the official ABR portal
Recommended Software
The following software products handle business compliance for Australian businesses: