Australian Company Numbers

What's an Australian Company Number (ACN)?

An ACN is a unique nine-digit number that every company in Australia has.

ACNs are managed by the Australian Securities and Investments Commission (ASIC).

Do I need an ACN?

If your business is a company, then you'll need an ACN. By law, an ACN must be shown on a number of documents, including:

• accounting statements, such as invoices

• any documents you lodge with ASIC

• receipts (if they're not machine generated, e.g. from a cash register)

• orders for goods and services

• business letterheads

• official company notices

• cheques, or any documents that represent a legal amount of payment

• written ads making a specific offer that can be accepted (such as by completing an order form).

If your company also registers for an ABN, then your ACN will form part of your ABN. In these cases, you won't need to display your ACN if your documents already display your ABN and company name.

For reasons why you may like to register an ABN for your company, check out our article on Australian Business Numbers.

How do I register for an ACN?

You are automatically given an ACN when you register a company with ASIC.

To find out more, read How to start a company on the ASIC website.