ABN vs ACN: two numbers, two different jobs
An ABN identifies a business for tax and invoices, an ACN identifies a company registered with ASIC, and this page sets out the difference between ABN and ACN in plain words.
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Which numbers your business structure typically uses
Pick your structure. These are general patterns, not rules for every case, so confirm your own situation with the ATO or your accountant.
Sole trader
A sole trader is a person trading in their own right. They typically use an ABN only. They won't have an ACN, because an ACN belongs to companies registered with ASIC. If they trade under a name other than their own, that name is registered as a business name and sits under their ABN.
Partnership
A partnership typically has its own ABN, separate from the partners' personal numbers. The partnership itself isn't a company, so it doesn't get an ACN. If one of the partners is a company, that partner has its own ACN.
Trust
A trust that runs a business typically has its own ABN. The trust isn't a company, so it has no ACN of its own. If the trustee is a company, the trustee company holds an ACN, which is why you may see both numbers on trust paperwork.
Company
A company gets its nine-digit ACN when it registers with ASIC. If it runs a business, it typically also holds an eleven-digit ABN. That ABN usually ends with the company's ACN, so the two numbers are linked.
Jump to the part you need
Compare the numbers side by side, see which ones your business structure uses, then read how a company's two numbers fit together.
ABN vs ACN vs business name, side by side
People mix up three identifiers, not two. Read across a row to compare one point, or down a column to see everything about one number. These rules come from the ATO and the Australian Business Register, so confirm them there.
| What you want to know | ABN | ACN | Business name |
|---|---|---|---|
| What it looks like | Eleven digits | Nine digits | Words, not a number |
| Who has one | Businesses of every structure, including sole traders | Companies registered with ASIC only | Any entity trading under a registered name |
| Where it comes from | Applied for through the Australian Business Register | Given when a company registers with ASIC | Registered with ASIC |
| Cost to apply | Free through the Australian Business Register | Not covered on this page | Not covered on this page |
| On a tax invoice | Yes, the seller's ABN must be shown | Not one of the required details | Can show who the seller is |
| Is it a company number | No | Yes | No |
| How it links to the others | A company's ABN usually ends with its ACN | Usually the last nine digits of the company's ABN | Sits under an ABN, and one ABN can hold several |
| Can you check it here | Yes, type it into the checker | Yes, type it into the checker | Yes, search by name and narrow the results |
Your ABN and ACN questions, answered plainly
This is general information only. Confirm your own situation with the ATO or your accountant before you rely on it.
Frequently Asked Questions
- Do I need both an ABN and an ACN?
- It depends on your structure. Sole traders, partnerships and trusts typically need an ABN only, because an ACN belongs to companies. A company gets an ACN when it registers with ASIC, and typically also holds an ABN if it runs a business. That ABN usually ends with the company's ACN.
- Which number goes on an invoice?
- A tax invoice must show the seller's ABN, along with the seller's identity, the issue date, what was sold, the amount charged and the GST details. An ACN isn't one of the required details. These rules come from the ATO, so confirm them on the ATO website.
- Can a sole trader have an ACN?
- No. A sole trader is a person trading in their own right, and an ACN belongs only to companies registered with ASIC. A sole trader uses an ABN. If they later set up a company, that company gets its own ACN as a separate entity.
- Can I find a company's ABN from its ACN?
- Often, yes. A company's ABN usually contains its ACN as its last nine digits. The simplest way is to type the ACN into our checker and read the matching result, rather than guessing the two extra digits yourself.
- Is a business name the same as a company?
- No. A business name is a trading name registered with ASIC. It doesn't create a company and it has no ACN. It sits under an ABN, and one ABN can hold several business names.
- Why does the checker say my number can't be real?
- The checker tests the check digits as you type. If a number fails, it can't be a valid ABN or ACN, which usually means a digit was mistyped or copied wrongly. Count the digits too: eleven for an ABN, nine for an ACN.
Got a number? Find out what it is.
Type an ABN, an ACN or a business name into one search box and see the status, entity type and GST details in seconds.