Australian Company Number (ACN)

ACN is the abbreviation for the Australian Company Number which is a unique, nine-digit number issued by the Australian Securities and Investments Commission (ASIC) upon the registration of a company.

A company’s ACN must appear on all ‘public documents’ and ‘eligible negotiable instruments’. Examples of documents where the ACN is required to appear include:

  • all documents lodged with ASIC;
  • statements of account, which includes all invoices;
  • receipts;
  • purchase orders for goods or services;
  • business letterheads;
  • official company notices;
  • cheques, promissory notes and bills of exchange; and
  • written advertisements making a specific offer.

Australian Company Number is contrasted with an Australian Business Number (ABN) in that an ABN is issued to all entities (in any capacity such as a sole trader or partnership etc.) that carry on a business, whereas Australian Company Number is only issued to a company when it is registered with ASIC.