ABN Lookup is a free public tool at abr.business.gov.au that searches the Australian Business Register in real time. It takes less than a minute and tells you whether an ABN is genuine, currently active, and registered for GST. For any new supplier relationship, it is the most basic due diligence step available and the one most commonly skipped.
What to actually check
Search the ABN from the invoice or the supplier's website. The result shows you the ABN status (Active or Cancelled), the legal entity name, the entity type, the state or territory of registration, and the GST registration status [ABR, abr.business.gov.au]. These are separate fields. An active ABN does not automatically mean the entity is registered for GST, and a GST registration that has been separately cancelled will not be obvious unless you check that field specifically [Lookup Tax, lookuptax.com].
If a supplier is charging you GST and their ABN Lookup result shows their GST registration as cancelled, the GST component of the invoice is not valid. Any input tax credits you claim against that invoice can be disallowed by the ATO on audit [Lookup Tax, lookuptax.com].
When a result comes back Cancelled
A cancelled ABN means the registration has been deactivated. This can happen because the business has closed, restructured, or because the ABR runs an automated process to cancel ABNs where there is no evidence of ongoing business activity, such as when no business income has been reported in recent tax returns [Lookup Tax, lookuptax.com]. The entity itself may still exist as a legal structure while its ABN is cancelled.
If a supplier's ABN is cancelled and you have already received an invoice, you are generally required to withhold 47% of any further payments to that supplier and remit it to the ATO as PAYG withholding, until they provide a valid active ABN [ATO, ato.gov.au].
What ABN Lookup does not tell you
It does not tell you whether a business is solvent, well-run, or capable of delivering what it has promised. It does not include a company's registered office address or director details, which sit on ASIC's separate companies register. It does not flag disputes, complaints, or regulatory findings against the entity. It is a basic identity check, not a comprehensive credit or solvency assessment.
If you want to check your own listing
Search your own ABN on ABN Lookup the same way you would check a supplier's. If your listed address, business name, or GST status looks outdated, update it through the ABR via the Relationship Authorisation Manager. Outdated details on ABN Lookup affect how potential clients and suppliers see your business before they ever contact you.
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