ABN vs ACN at a glance
An ABN (Australian Business Number) is 11 digits. It identifies any entity registered in the Australian Business Register — companies, sole traders, partnerships, trusts, and other entity types.
ASIC assigns a separate identifier to registered companies: the ACN (Australian Company Number), a 9-digit number issued under the Corporations Act 2001. No other entity type receives one.
The fastest way to tell them apart? Count the digits. 11 means ABN. 9 means ACN. If an entity has an ACN, it is a registered company. If it only has an ABN, it is some other structure — a sole trader, partnership, trust, or similar.
A sole trader plumber has an ABN but no ACN. A Pty Ltd construction firm has both.
Why the distinction matters
When you look up an ABN record in the Australian Business Register, you may notice an ASIC number alongside the ABN. Here is what that tells you:
- Broader vs narrower. The ABN covers every entity type in the Australian Business Register. The ACN covers only companies registered with ASIC. Seeing both means the entity is a company.
- Separate registries. The ABN comes from the Australian Business Register. The ACN comes from ASIC. These are separate systems maintained for different regulatory purposes.
- Different documents. ABNs appear on invoices, tax documents, and business registrations across all entity types. ACNs appear on company-specific documents — annual returns, ASIC filings, and corporate records.
If you are checking a supplier, contractor, or business partner, knowing whether they hold an ACN tells you they operate as a registered company rather than a sole trader or partnership.
How ABN records display ASIC numbers
When you read an ABN record, you may see an ASIC number field. That field appears when the entity is a registered company. It comes from the public record data in the Australian Business Register and connects the ABN record to the entity's company registration.
For company-specific details — directors, share structure, compliance history — check the ASIC company register directly. ABN Signal shows only what appears in the public ABN record.
What seeing both identifiers tells you
When an ABN record includes an ACN, the entity is a registered company with parallel registrations in the ABR and ASIC systems. The ABN identifies it for tax purposes; the ACN identifies it as a registered company. Together, they confirm corporate entity status.
For a full company profile — directors, shareholders, annual returns — check the ASIC register directly.