An Australian Business Number (ABN) is the foundation of every legitimate business operating in Australia. It is free to obtain, identifies your business to the government and other businesses, and is required for invoicing, GST registration, business banking, and domain name registration.
This guide covers who needs an ABN, how to apply, what happens after approval, and the ongoing obligations that come with having one.
Table of Contents
- What is an ABN?
- Who needs an ABN?
- Who is eligible?
- What you need before applying
- How to apply for an ABN
- What happens after you apply
- What to do with your ABN
- ABN and your business address
- Cancelling or updating your ABN
- Frequently asked questions
What Is an ABN?
An ABN is a unique 11-digit number issued by the Australian Business Register (ABR) that identifies your business to the government and to other businesses.
It is separate from your Tax File Number (TFN), which is a personal identifier — an ABN is a business identifier.
Your ABN appears on:
- All tax invoices you issue to clients
- Business Activity Statements (BAS) lodged with the ATO
- Your business name registration with ASIC
- Your Google Business Profile
- Any government grant or procurement applications
- Your business bank account application
Without an ABN, businesses you work with are legally required to withhold 47% tax from payments to you (the "no-ABN withholding" rule).
This is a significant and avoidable problem.
Who Needs an ABN?
You need an ABN if you are:
- Carrying on a business in Australia (regardless of size — even part-time freelancing counts)
- Required to register for GST (because your turnover meets or exceeds $75,000)
- A contractor or freelancer who invoices clients
- Registering a business name with ASIC
- Applying for a .au domain name
- Wanting to receive payments from other businesses without having tax withheld
You Do Not Need an ABN If:
- Your activities are purely a hobby with no commercial intent
- You are an employee receiving salary or wages (your employer withholds PAYG tax; you do not need an ABN)
- You occasionally sell personal assets (such as selling furniture on Facebook Marketplace) without running a regular trading operation
The distinction between a hobby and a business matters.
The ATO considers factors including:
- Whether you operate in a businesslike manner
- Whether you intend to make a profit
- Whether your activity is repetitive and organised
If you are unsure, the ATO's hobby vs business decision tool at ato.gov.au can help.
Who Is Eligible?
You are eligible for an ABN if you are carrying on or starting an enterprise in Australia.
This includes:
- Australian residents operating a business of any size or structure
- Non-residents operating a business in Australia or through Australian-based activities
- Individuals (sole traders), partnerships, companies, trusts, and non-profit organisations
- Foreign companies establishing an Australian presence
You Are Not Eligible If:
- You are purely an employee (no business activity)
- Your activities are hobby-based with no genuine commercial intent
- You are applying speculatively without any genuine business activity planned
The ABR takes eligibility seriously.
Providing false information on an ABN application is a serious offence.
What You Need Before Applying
Gather the following before starting your application.
For All Applicants
- Your Tax File Number (TFN) — or your business's TFN for companies and trusts
- Full legal name and date of birth
- Your residential address
- Contact details (phone and email)
- A description of your primary business activity (use ANZSIC industry codes — the application will guide you)
- Your intended business start date (can be backdated up to 6 months)
- Your business address (principal place of business and postal address)
For Companies
- Your Australian Company Number (ACN) — obtained when you register the company with ASIC
- Details of all directors
For Partnerships
- Details of all partners including their TFNs
For Trusts
- Details of the trustee and beneficiaries
How to Apply for an ABN
There are two ways to apply.
Option 1: Australian Business Register (ABR)
Go to abr.business.gov.au and select "Apply for an ABN."
You will need a myGovID digital identity to use this portal.
The application is guided and typically takes 15–30 minutes to complete.
Option 2: Business Registration Service (Recommended)
The Business Registration Service at register.business.gov.au allows you to apply for:
- An ABN
- A business name
- Company registration
- GST registration
in a single transaction.
If you are starting a new business and need multiple registrations, this is the most efficient approach.
Step-by-Step Through the ABR Application
1. Check Eligibility
Answer the eligibility questions honestly.
If you are not eligible, do not proceed.
2. Select Your Business Structure
Choose:
- Sole trader
- Company
- Partnership
- Trust
- Other
Your structure determines which fields you need to complete.
3. Enter Personal/Entity Details
Provide:
- TFN
- Full name
- Date of birth
- Contact information
4. Describe Your Business Activity
Select the ANZSIC code that best describes your primary activity.
You can select multiple codes if your business spans different activities.
5. Enter Your Business Address
Provide:
- Principal place of business (where you operate)
- Postal address (where you receive mail)
These can be different addresses.
A virtual address from Space Penguin is accepted for both.
6. Enter Your Business Start Date
This can be:
- Today's date
- A historical date (backdated up to 6 months)
- A future date
7. Review and Submit
Check all details carefully.
Incorrect information can cause delays and may require a formal amendment.
What Happens After You Apply
Instant Approval (Most Common)
If your application is straightforward and your identity can be verified automatically, the ABR typically issues your ABN immediately.
You receive an 11-digit number that is active from your nominated start date.
Delayed Processing
In some cases particularly for new applicants without an established identity history with the ATO processing can take up to 28 days.
The ABR will notify you of any additional information required.
Rejection
If the ABR determines you do not meet the eligibility criteria (for example, your activity appears to be a hobby), your application will be refused.
You can reapply if:
- Your circumstances change
- You can provide additional evidence of business activity
Once approved, your ABN is listed on the public ABN Lookup tool at abr.business.gov.au, where anyone can search your business name or ABN and see your registration details.
What to Do With Your ABN
Include It on All Invoices
Every tax invoice you issue to a client must include your ABN.
Without an ABN on your invoice, your client is required to withhold 47% of the payment.
Register for GST If Required
If your annual turnover is $75,000 or more (or you expect it to reach this within 12 months), register for GST through the ATO.
Once registered:
- Add 10% GST to your invoices
- Lodge a BAS quarterly or monthly
Register a Business Name (If Needed)
If you want to trade under a name other than your own legal name, register a business name with ASIC at connect.asic.gov.au.
Open a Business Bank Account
Use your ABN and business address to open a dedicated business bank account.
Keeping business and personal finances separate from day one makes tax time significantly easier.
Update Your Business Details When They Change
You are legally required to update your ABN registration within 28 days of any change, including:
- Address
- Business structure
- Business activities
- Contact details
ABN and Your Business Address
When you register an ABN, you provide:
- A principal place of business
- A postal address
These are visible on the public ABN Lookup tool, although since 2021 residential addresses are hidden from public view on ABN Lookup.
However, if you register a business name with ASIC, your service address is published on the ASIC public register and is fully searchable.
Using a virtual address from Space Penguin means this publicly searchable address is a professional commercial street address rather than your home.
A virtual address can be used as:
- Your ABN principal place of business (if you genuinely manage the business from that location, or as a correspondence address)
- Your ABN postal address
- Your ASIC business name service address
This is legal, commonly done, and recommended for anyone who values their privacy.
Cancelling or Updating Your ABN
Updating Your ABN
Log in to the ABR portal and update your details.
Common updates include:
- Business address
- Contact information
- Business activity codes
Changes take effect immediately.
Cancelling Your ABN
If you close your business, you should cancel your ABN through the ABR.
Holding an ABN you are no longer using can cause issues with the ATO and may require ongoing tax return lodgements.
Cancellation is free and can be done online.
What Happens to a Cancelled ABN?
Cancelled ABNs remain searchable on the public ABN Lookup with a "cancelled" status.
The number is not reissued.
Frequently Asked Questions
How Much Does an ABN Cost?
Nothing.
ABN registration is free through the Australian Business Register.
Be cautious of third-party services that charge fees to apply on your behalf while some provide additional support, the registration itself is free.
How Long Does ABN Registration Take?
Most applications receive instant approval.
In some cases, processing takes up to 28 days.
Can I Have More Than One ABN?
Generally, no.
Each business entity has one ABN.
If you operate multiple businesses under the same legal entity (for example, a sole trader with several revenue streams), they all share the same ABN.
If you operate separate legal entities (for example, two different companies), each entity has its own ABN.
What Is the Difference Between an ABN and a TFN?
Your TFN (Tax File Number) is a private identifier for you as an individual.
It is not displayed publicly and is used for personal income tax purposes.
Your ABN is a public business identifier used for commercial and tax purposes and appears on:
- Invoices
- Public registers
- Government records
Do I Need to Register for GST When I Get My ABN?
Only if:
- Your annual turnover is $75,000 or more
- You are a taxi driver or rideshare provider
Below the $75,000 threshold, GST registration is optional.
You may choose to register voluntarily if it suits your clients, particularly if you work with GST-registered businesses that want to claim input tax credits.
Can I Use My ABN to Invoice Before My Business Officially Starts?
Your ABN can be backdated up to 6 months, allowing you to invoice for work completed before you registered.
You cannot invoice for work completed more than 6 months before your ABN registration date.
Setting up your business? Space Penguin provides a professional business address for your ABN registration Sydney and Melbourne from $20/month.