Australian Company Number
| Company type | Identifier |
|---|---|
| Industry | Corporate registration |
| Founded | July 1, 2000 |
| Founder | Australian Securities & Investments Commission |
Area served | Australia |
| Website | asic |
An Australian Company Number (ACN) is a distinctive nine-digit code assigned by the Australian Securities & Investments Commission (ASIC) to every company registered under Australia’s Corporations Act 2001 (Cth). This number is structured into three sets of three digits and is always prefixed by "ACN." It is mandatory to include the ACN on all official company documents and invoices.
In addition to the ACN, companies might also require a Tax File Number (TFN) and an Australian Business Number (ABN). When a company holds an ABN, it can use this identifier in place of the ACN on documentation, with "ABN" preceding the number. Similar nine-digit identifiers, known as Australian Registered Body Numbers (ARBN), are allocated to non-company entities and foreign companies.
History
The ACN system was established on 1 July 2000, coinciding with the introduction of the GST. At that time, ASIC issued ACNs to all existing registered companies. Any company registered under the Corporations Act 2001 is assigned an ACN upon registration.
Companies are required to display their ACN on official seals, public records, negotiable instruments, and all ASIC submissions. However, the ACN is not obligatory on packaging, general advertising materials, credit cards, machine-generated receipts, business cards, or items not considered documents such as vehicles or television advertisements.
An ACN remains constant throughout a company's existence, unaffected by any changes in its name or deregistration status.
Relationship to ABN
The implementation of the GST also introduced the Australian Business Number (ABN), alongside reforms affecting sales tax exemptions and fringe benefits tax. Generally, a company's ABN incorporates its ACN as the final nine digits. The ABN is crucial for entities registered with the Australian Business Register (ABR) that engage in business activities and facilitates smoother dealings with government bodies like the Australian Taxation Office for GST-related matters.
Where applicable, companies may substitute their ACN with their ABN on official paperwork.
Examples
- ACN 000 000 019, 007 249 989, 005 749 986
- ABN 53 004 085 616
Format of ACNs and ABNs
The ACN consists of nine digits generated through a specific algorithm, with the final digit serving as a check digit used for validation purposes. In contrast, the ABN contains eleven digits; its first two digits function as check digits. The last nine digits of an ABN do not necessarily conform to the ASIC ACN algorithm—for example, the Australian Taxation Office has an ABN of 51 824 753 556.
Purpose of unique identifiers
Prior to adopting the nine-digit ACN system, ASIC filings were primarily based on company names, which varied significantly in length and often led to errors and inefficiencies—particularly when names were similar (e.g., Strudle Pty Ltd versus Stradle Pty Ltd). The introduction of unique identifiers such as the ACN was aimed at minimizing fraud and mistakes by distinctly identifying companies and their subsidiaries even when names closely resembled each other. Notably, a company’s ACN remains stable regardless of any name changes or in instances involving phoenix company restructuring.