Quick answer
An ABN (Australian Business Number) is a free, unique 11-digit number the Australian Business Register issues to anyone carrying on an enterprise in Australia. It identifies your business to the ATO, other businesses and lenders. Business lenders look it up to confirm the business is real and active, check its GST status, and measure how long you've been trading from the date it became active.
Key points
- Eleven digits: two check digits followed by a nine-digit identifier
- Free to apply for through the Australian Business Register, but only if you're running an enterprise
- Most lenders count your time in business from the date your ABN became active
- ABN Lookup shows anyone your ABN status, entity type and GST registration
Your ABN is the number that tells government agencies, suppliers, customers and lenders who your business is. It’s an 11-digit identifier issued free of charge by the Australian Business Register (ABR) to people and entities carrying on an enterprise, and it sits alongside your tax file number rather than replacing it.
What the 11 digits actually mean
The first two digits are check digits. The remaining nine identify the entity. For a company, those nine are usually its ACN, which is why a company’s ABN so often looks like its company number with two digits stuck on the front.
The check digits let software catch a typo before an invoice goes out. The ABR publishes the method: take one off the first digit, multiply each digit by a fixed weight (10, 1, 3, 5, 7, 9, 11, 13, 15, 17, 19), add the results, and divide by 89. A genuine ABN leaves no remainder. The ABR’s own example, 51 824 753 556, works out to 534, which is exactly six lots of 89.
You don’t need to do this by hand, but it explains why lenders’ systems reject an application instantly when one digit is wrong.
Who can get one
You’re entitled to an ABN if you’re carrying on an enterprise in Australia: a sole trader, partnership, company, trust or similar. Employees and hobbyists aren’t. Applying is free through the ABR. If everything checks out you usually get the number as soon as you submit the form; applications sent for manual review can take around 20 business days.
Watch for websites that charge a fee to “register” an ABN for you. The government service costs nothing.
Why lenders care so much about your ABN
When you apply for business finance, the ABN is one of the first things a credit assessor types in. ABN Lookup is public, so in a few seconds they can see:
| What ABN Lookup shows | What the lender reads into it |
|---|---|
| ABN status and the date it became active | How long you’ve been trading |
| Entity type (individual, company, trust, partnership) | Who signs and who guarantees |
| GST registration and date | A rough signal that turnover has passed $75k |
| Business and trading names | Whether the name on your bank statements matches |
The active-from date matters most. Most lenders treat it as your trading start date. Banks typically want two years; many non-bank lenders will look at six or twelve months. If your number is newer than that, our pages on loans with an ABN under 6 months and ABN under 12 months set out what’s realistic.
GST status is the other quiet signal. A business that says it turns over $400k a year but isn’t registered for GST will get questions, because registration is compulsory once turnover reaches $75k.
Not sure which product fits your trading history? Tell us about your business and we’ll point you in the right direction.
Example: the restructure that reset the clock
Priya ran a landscaping business as a sole trader for four years. On her accountant’s advice she moved into a company, which received a fresh ABN in March. In August she applied for a $90k loan to buy a second ute and a trailer.
The first lender’s system saw an ABN only five months old and declined automatically. The business hadn’t changed: same customers, same phone number, same truck. The fix was simple. On her next application Priya included her old ABN, two years of BAS from the sole trader period and a note from her accountant explaining the restructure. The assessor counted her four years of history and the loan was considered on its merits.
If you’ve changed structure, say so up front rather than letting a system judge you on a new number.
Related terms
- ACN: the company number ASIC issues, often embedded in a company’s ABN
- GST: registered separately, and visible on ABN Lookup
- BAS: the statements lenders use to confirm turnover in low doc business loans
- Sole trader: the simplest structure that can hold an ABN
Got an ABN and a reason to borrow?
Whether your ABN is six weeks or sixteen years old, there’s usually a lender whose criteria fit. Our guide to registering a business name and ABN covers the set-up side; when you’re ready to talk money, the enquiry form takes roughly a minute. Asking costs nothing on your credit file, because no credit check happens at the enquiry stage. Your details stay with us instead of being blasted out to a crowd of lenders, and someone real reads your answers and phones you. Give us your true ABN date and turnover so the first option we suggest is one you can actually get.
Frequently asked questions
How long does my ABN need to be active to get a business loan?
It depends on the lender and the product. Banks usually want two years or more of trading with financials. Many non-bank lenders will look at six to twelve months, and some property-secured lenders will consider a newer ABN if there's solid equity behind the loan.
Is an ABN the same as an ACN?
No. The ATO-run Australian Business Register issues ABNs to any enterprise, including sole traders, partnerships and trusts. ASIC issues an ACN only to a registered company. Most companies hold both, and the company's ABN usually ends with its ACN.
I moved from sole trader to a company. Does my trading history reset?
The company gets a new ABN, so a lender looking only at the new number may think you're brand new. Tell the lender about the earlier ABN and supply its history, such as BAS and tax returns, so your full trading record counts.
Does having an ABN mean I'm registered for GST?
No. GST registration is separate. You must register for GST once your turnover reaches $75k, and ABN Lookup shows whether a business is registered and from what date.
Can I get a business loan without an ABN?
Business loans are for business purposes, so almost every lender will want an ABN. If you're just starting, register the ABN first; it's free and the online application often gives an answer straight away.