Australia ABN Validation
Validate Australian Business Number (ABN) Online
Verify ABN status, entity type, and GST registration for free. Check 11-digit format and validate against the Australian Business Register (ABR).
Understanding Australia ABN Format
The Australian Business Number (ABN) is a unique 11-digit identifier. It is distinct from the 9-digit ACN (Company Number).
Digits
Identifier (ACN)
- ✓ Structure: 11 digits total. The first two are check digits calculated using a Modulus 89 algorithm.
- ✓ ABN vs ACN: For companies, the last 9 digits are usually their Australian Company Number (ACN).
- ✓ No Letters: An ABN is strictly numeric. It never contains letters.
Frequently Asked Questions
What is the difference between ABN and ACN?
An ABN (11 digits) is for all businesses dealing with tax/government. An ACN (9 digits) is only for registered companies. If you have an ACN, your ABN is usually just "Check Digits + ACN".
Where can I check an ABN status?
You can check it on the government's ABN Lookup website or use our API. Our tool checks if the ABN is "Active" or "Cancelled" and whether it is registered for GST.
How do I find a company's ABN?
By law, businesses must display their ABN on invoices, receipts, and their website footer. If a supplier refuses to provide an ABN, you may need to withhold 47% of the payment.
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