ABN number: what it is, who needs one and how to apply

Published Monday 20 April 2026

Table of contents

• What is an ABN?
• Why do you need an ABN?
• What are the advantages of having an ABN?
• Who needs to apply for an ABN?
• What you need to apply for an ABN
• How to apply for an ABN
• What happens after you apply for an ABN?
• How to check an ABN
• Getting your ABN sorted
• FAQs on ABNs

Key takeaways

• Apply for your ABN early in your business setup, as most business activities require one and operating without it means other businesses must withhold 47% tax from payments they make to you.
• Gather your Tax File Number, business structure details, and contact information before you start your ABN application, so you can complete the free online process in 10–15 minutes.
• Register for GST within 21 days of your annual earnings reaching $75,000, as this is a legal requirement that comes alongside holding an ABN at that income level.
• Use the ABN Lookup tool on the Australian Business Register website to verify the ABN of any business you deal with, confirming their registered name and GST status before you transact.

What is an ABN?

An Australian Business Number (ABN) is a unique 11-digit number that the government uses to recognise your business. It's free to apply for and stays with your business for as long as you operate.

You'll use your ABN when dealing with:

• government agencies like the ATO
• other businesses as suppliers or customers
• the public for transactions and invoicing

Why do you need an ABN?

Most Australian businesses are legally required to have an ABN. Beyond compliance, an ABN unlocks essential business functions.

You need an ABN to:

• register a business name with ASIC (fees to register start at $45 for one year or $104 for three years)
• secure a .com.au domain for your website
• access digital services like eInvoicing
• avoid tax withholding on business payments

What are the advantages of having an ABN?

An ABN establishes your business as legitimate with suppliers, customers, and government agencies. Most businesses expect you to provide an ABN before they'll work with you.

With an ABN, your business can:

• claimGST credits: recover GST on business purchases when registered
• avoid tax withholding: keep your full payment instead of losing nearly half to tax
• access business accounts: sign up with suppliers like telcos and energy providers
• register a .com.au domain: secure your Australian web presence
• apply for grants: qualify for government support payments
• employ staff: hire workers and meet payroll obligations

Without an ABN, other businesses must withhold tax from payments more than $75 (excluding GST). The ATO requires them to withhold the top rate of tax, which is 47%, from the payment. While you can claim this back at tax time, it creates cash flow problems.

Apply for your ABN early in your business setup process. Most business activities require an ABN, so getting one upfront prevents delays in operations.

Who needs to apply for an ABN?

Most businesses operating in Australia need an ABN. This includes sole traders, partnerships, companies, and trusts conducting business activities.

Your ABN and GST requirements depend on your situation:

• if you earn over $75,000 annually: you must have an ABN and register for GSTwithin 21 days of meeting the requirement
• if you earn under $75,000 annually: you can apply for an ABN and register for GST later
• if you drive for taxi or ride-share services: you must register for GST regardless of turnover

Read more about who is entitled to get an ABN on the Australian Business Register website.

You should seek professional advice from an accountant or lawyer before deciding whether to apply. Visit the Xero advisor directory if you need help finding someone.

What you need to apply for an ABN

Gather this information before you start your application:

• your Tax File Number (TFN)
• your business structure, such as sole trader, partnership, company, or trust
• your business name, if different from your personal name
• your business address and contact details
• a description of your main business activity

How to apply for an ABN

ABN applications are free and processed through the Australian Business Register (ABR). The online application typically takes 10–15 minutes.

Here's how to apply:

1. Visit the Australian Business Register website and select "Apply for an ABN"
2. Choose your business structure (sole trader, partnership, company, or trust)
3. Enter your personal details and Tax File Number
4. Describe your main business activity
5. Add your business name and contact information
6. Review your application and submit

Read our detailed guide on how to apply for your ABN for more information.

What happens after you apply for an ABN?

Most ABN applications are approved instantly. If your details are correct and can be verified automatically, you'll receive your 11-digit ABN straight away.

Some applications require manual review, which can take up to 20 business days. This happens when:

• your identity can't be verified automatically
• your business structure needs clarification
• additional information is required

You can check the status of your application on the ABR website.

Common reasons your ABN application might be rejected

Most applications succeed, but rejections can happen if:

• you're not entitled to an ABN (not carrying on a business)
• your identity can't be verified
• your business structure details are incorrect
• you've provided incomplete information

If your application is rejected, you'll receive a letter explaining why and what to do next.

How to check an ABN

The ABN Lookup tool lets you verify any business's ABN for free on the Australian Business Register website. Use it to confirm the legitimacy of businesses you're dealing with.

ABN Lookup shows you:

• the business's registered ABN
• their official business name
• whether they're registered for GST
• when their ABN was registered

Getting your ABN sorted

Your ABN helps you avoid tax withholding and opens doors to essential services.

Once you have your ABN, add it to your invoices and business documents, and update your details within 28 days if they change to stay compliant. Accounting software like Xero makes this simple by letting you set up invoice templates with your ABN included automatically.

Try Xero free for 30 days and see how easy managing your business finances can be.

FAQs on ABNs

Here are answers to common questions small business owners ask about ABNs.

What happens if I operate without an ABN when I need one?

Businesses must withhold tax from payments they make to you if you don't provide an ABN. The ATO requires them to withhold the top rate of tax, which is 47%, from the payment.

Operating without an ABN also makes it harder to deal with government agencies.

How long does it take to get an ABN approved?

See the section above on what happens after you apply for an ABN.

Can I start using my ABN immediately after applying?

Yes, if your application is approved and you receive your ABN immediately, you can start using it for business purposes right away.