What is the difference between an ABN and an ACN?

An ACN and an ABN are both identifying numbers, but they do different jobs. The ACN identifies a company. The ABN identifies a business of any type, including a company.

The short version

	ACN (Australian Company Number)	ABN (Australian Business Number)
Length	9 digits	11 digits
Who has one	Companies only	Any type of business that is entitled, including sole traders, partnerships and companies
Who issues it	ASIC, when the company is registered	Applied for through the Australian Business Register (ABR). ASIC notes the ABN is issued by the ATO, not ASIC
Main purpose	Identifies the company	Identifies your business to government and the community, including in the GST system
Where to check it	ASIC’s company register	ABN Lookup

What an ACN is

An ACN is a unique 9-digit number that identifies a company. ASIC issues every company with an ACN when it is registered.

If you register a company through the Business Registration Service, ASIC processes the registration. The confirmation email includes the company’s ACN and a certificate of registration.

A company must show its ACN on many documents, including invoices and statements of account, receipts that are not machine-produced, orders for goods or services, business letterhead and documents lodged with ASIC. ASIC says the company’s full name and ACN must appear on the first page of every document where they are required.

Some items don’t need the ACN, such as machine-generated receipts, business cards, envelopes and vehicles.

What an ABN is

An ABN is an 11-digit number used to identify any type of business, including sole traders, partnerships and companies. You apply for an ABN through the ABR, and you need to be entitled to one. The ABR says a Corporations Act company is entitled to an ABN.

For more on eligibility and applying, see how to get an ABN.

How the ABN relates to the ACN for a company

Most companies have both numbers. ASIC says a company’s ABN is often the same as its ACN, with 2 extra numbers at the beginning. ASIC’s example is:

• ACN: 123 456 789
• ABN: 36 123 456 789

The order matters. The ATO says that if you run your business through a company, you register the company with ASIC and get an ACN first. You need your ACN before you can get your ABN and tax registrations.

Directors also need a director ID before the company is registered. That is a third, separate number that identifies you as a person. See how to apply for a director ID.

Step by step: how to find your ACN

1. Check your registration documents. If you registered through the Business Registration Service, your confirmation email includes the ACN and your certificate of registration.
2. Search ASIC’s company register. Go to ASIC’s company and organisation registers page and search within organisation and business names. You can search by company name or ACN.
3. Read the free details. ASIC says basic information is free, including the company name and type, the ABN and ACN, the registration date, the next review date, and the suburb, state and postcode of the registered office.
4. Or use ABN Lookup. ABN Lookup lets you search by ABN, ACN or name. No login is needed.

Step by step: how to find your ABN

1. Search ABN Lookup by your business name, ACN or ABN.
2. Check the record. ABN Lookup shows whether an ABN is active or cancelled, the business type, GST status and other public details provided to the ABR.

Important things to know

• Sole traders don’t have an ACN. Only companies do. A sole trader or partnership uses its ABN.
• The ACN comes first for companies. You can’t get the company’s ABN until ASIC has registered the company and issued the ACN.
• Show your ACN where required. ASIC sets out which documents must show your company’s name and ACN. Check its list before you print invoices, receipts or letterhead.
• Paid ASIC records cost extra. Basic company details are free to search. ASIC charges for more detailed information, such as company extracts and copies of documents.
• Neither number is your director ID or TFN. Your director ID identifies you as a director. The ATO says a company must also apply for its own tax file number.
• Choosing a structure? Whether you need an ACN depends on whether you use a company. See sole trader vs company.