Australian Company Numbers
Every company in Australia is issued with a unique, nine-digit number when registered. This is an Australian Company Number (ACN) and must be displayed on all company documents.
A company's ACN must be on all 'public documents' and 'eligible negotiable instruments'. The items on which it should appear include:
- all documents lodged with ASIC
- statements of account, including invoices
- receipts (which are not machine-produced)
- orders for goods and services
- business letterheads
- official company notices
- cheques, promissory notes and bills of exchange, and
- written advertisements making a specific offer.
A company's name and ACN must appear on the first page of any documents.
When multiple companies are on a document (eg. a letterhead), the ACN for each company must be displayed next to each company's name.
The ACN must always be clear, easily readable, and obvious as to which company it belongs to.
The ACN can be referred to by the words 'Australian Company Number', or abbreviations 'ACN' or 'A.C.N.'
If your company has an Australian Business Number (ABN), you may use the ABN in place of the ACN on documents. You must make sure that:
- your ABN includes your nine digit ACN, and
- the ABN is used in the same places that the ACN is used.
For more information about Australian Business Numbers, contact the Australian Taxation Office.
A company may have a common seal and use it to execute documents under its constitution. It's not compulsory for a company to have a common seal. If a company does have a common seal, it must include:
- the company’s name, the expression 'Australian Company Number' and the company’s ACN, or
- if the company uses its ABN instead of the ACN -the company’s name, the expression 'Australian Business Number' and the company’s ABN
Note that ASIC does not issue common seals.
A company may make contracts and execute documents without using a seal.
The items on which the ACN is not required include:
- packaging and labelling, including envelopes and transport documents
- advertisements which do not make a specific offer (such as advertisements which only promote the company)
- credit cards and credit card vouchers
- machine-generated receipts, including cash-register receipts
- business cards and 'with compliments' slips, and
- items which are not documents (e.g, vehicles, television advertisements