Company Registration Number Check: Same Legal Entity on Every Supplier Document

This article is provided for information only and is not legal advice. References are accurate as of 24 October 2026. Check current rules with a qualified professional before applying them to a specific supplier file.

A company registration number check on an Australian supplier confirms that the ABN or ACN written on a document belongs to a real entity and that the name, status and GST details match what the public records show. Australia uses two identifiers that people routinely confuse: the ABN, held on the Australian Business Register, and the ACN, allocated by ASIC to a company. This guide sets out which field on which document is compared with which record, what a mismatch looks like and what the reviewer does next.

Which identifier belongs to which entity?

The ABN is an 11-digit identifier for entities on the Australian Business Register, and the ACN is a nine-digit number that ASIC allocates when a company is registered; a company usually has both. Write down which one each document shows before comparing.

The Australian Business Register describes the ABN as a unique 11-digit identifier whose first two digits are check digits (ABR). Its glossary explains that an ABN can be active or cancelled, that the entity name can differ from the business name, that the record shows whether and when the entity is registered for GST, and that an ACN is a nine-digit number allocated by ASIC (ABR glossary). ABN Lookup can be searched by business name, company name or ACN.

What does the cross-check matrix look like?

An Australian supplier file needs at least seven cross-checks, each with a defined failure pattern. This is the core of the process.

Normalize before comparing. Strip "Pty Ltd" and "Limited" for a first pass, then compare the full name. "Pty Ltd" versus "Pty Limited" is formatting. "Pty Ltd" versus "Trust" is a different legal structure.

What does each lookup prove?

A register lookup shows the public record of the entity; it does not authenticate the PDF in front of you.

I did not verify the exact set of fields that ASIC Connect returns to the public or its fees for this article, so check the ASIC site for the current extract options before writing them into a procedure.

Which mismatches are harmless and which are red flags?

A sole trader can legitimately hold an ABN with no ACN. Their file needs different evidence from that of a company, and the reviewer should not demand an ACN that cannot exist.

What do users ask about this check?

Users on specialized forums often ask two things. The first: "Is the ABN the same as the ACN?" No. A company has an ACN from ASIC and usually an ABN as well, and the ABN of a company is commonly built on its ACN, but they are separate identifiers and the file should record both. The second: "How do I know the ABN on an invoice is real?" Search it on ABN Lookup and compare the entity name, the status and the GST registration with the invoice. A match shows the number exists and is current; it does not show the invoice is genuine.

How do you run the check step by step?

1. Extract name, ABN, ACN, address and GST claim from each document, keeping the document type next to each value.
2. Search ABN Lookup by ABN, and the ASIC record by ACN if the supplier is a company. Save the results with the date.
3. Compare each extracted value using the matrix above.
4. Classify each difference as formatting, alias or identity.
5. For identity differences, contact the supplier through a channel from the record or a prior contract, not from the document in question.
6. Record the decision and evidence in the supplier file.

For the document list, see our supplier onboarding documents checklist and the article on cross-document verification. The overall method is in the document verification guide.

How can the check be automated?

CheckFile compares the fields extracted from each document, such as entity name, ABN, ACN, GST claim, address and account holder, with each other and with the register data you supply, and lists the differences for a reviewer. It does not decide that a document is authentic; it shows where the file is inconsistent so a person can act. See how document validation works and the pricing.

FAQ

What is a company registration number check in Australia?

It is a comparison of the ABN or ACN and the name on a document with ABN Lookup and, for companies, the ASIC record. It confirms the entity exists and shows its public status.

Is the ABN the same as the ACN?

No. The ABN is on the Australian Business Register and can belong to any entity type; the ACN is allocated by ASIC to a company. Record both and tie them to the same name.

Does ABN Lookup prove the invoice is genuine?

No. It shows the public record of the entity, including status and GST registration. A forged invoice can still quote a real ABN, so name, GST claim and bank account holder must also match.

How often should the check be repeated?

At onboarding, when the supplier changes bank details or address, and at each periodic review. An ABN can be cancelled, so an old check says little about today.