Australia · AU
The Australian Business Number
Australia has no VAT. It has the GST, and the number an invoice carries is the ABN — eleven digits with a checksum you can verify without asking anyone.
Format: AU + 11 digits
Example: AU11000000948
Issued by: the Australian Business Register, run by the Australian Taxation Office.
The format
An ABN is eleven digits, written in groups of 2-3-3-3 on paper and stored without spaces. The first two digits are a check on the other nine, and the rule is public:
- −1Subtract 1 from the leading digit.
- ×Multiply the eleven digits by 10, 1, 3, 5, 7, 9, 11, 13, 15, 17, 19.
- mod 89The sum divides by 89 exactly.
That makes Australia one of the few countries where a typo can be caught before any network call is made — the same class of offline check as the French key or the Polish NIP.
An ABN is not a GST registration
This is the distinction to get right, and it is the Australian equivalent of "an organisation number is not a VAT number".
An ABN identifies an entity carrying on an enterprise. GST registration is separate, compulsory above a turnover threshold and optional below it. A sole trader under the threshold, a self-managed superannuation fund, a dormant company: all hold an active ABN, none charges GST.
The register publishes both, as two fields with two dates, and Vatlas keeps them apart. An entity with an active ABN and no GST registration comes back as not_registered — named, addressed, and explicitly not charging GST. Reporting it as inactive would say the opposite of what the register says.
ABN, ACN and ARBN
A company registered with ASIC also has a nine-digit ACN, and its ABN is usually those nine digits with two more in front. A foreign company registered in Australia has an ARBN instead. Entities that are not companies — sole traders, partnerships, trusts, government bodies — have an ABN and nothing else, which is then the only identifier there is.
Finding the entity behind the number
The ABN Lookup bulk extract
The ABR publishes the whole public register weekly, in XML, on data.gov.au, under CC-BY, with no account and no key. Twenty files of some 630 MB, keyed by the ABN itself. It is one of the cleanest open registers of any country on this site, and it is what Vatlas imports.
What the extract does not contain
An address, in the sense most countries mean it. The ABR publishes the state and the postcode of the main business location and no street at all. That is a deliberate limit of the register and not of the import: no source will give you an Australian street address from an ABN for free.
Australia-specific pitfalls
- An active ABN does not mean GST is charged. The two statuses are independent and both are published.
- No street address. State and postcode is all the register holds.
- The legal name is not the trading name. An entity can carry a dozen registered business names; the extract lists them all and only one of them is its name.
- Cancelled ABNs stay in the file. They are marked
CAN, with the date, rather than removed.
One API, inside Europe and out
Vatlas turns a business tax number into a company record: legal name, national identifier, legal form, status and address. Same call, same shape, for an ABN and for a French VAT number.
curl "https://api.vatlas.dev/v1/lookup/AU11000000948" \
-H "Authorization: Bearer $VATLAS_KEY"Response:
200 OK
{
"data": {
"vatNumber": "AU11000000948",
"countryCode": "AU",
"nationalId": "000000948",
"name": "QBE INSURANCE (INTERNATIONAL) LTD",
"legalForm": "Australian Public Company",
"status": "active",
"address": {
"line1": null,
"line2": null,
"postalCode": "2000",
"city": "NSW",
"country": "AU"
}
},
"meta": {
"source": "ABR",
"sourceDate": "2026-09-03"
}
}meta.sourceDate is the day the extract was published, not the day you asked. The shape of the response never changes from one country to the next.
Free to try. An email address is all it takes to create an account, with 100 requests a month and a working key in about a minute.
Frequently asked
The ABN in short
How many digits does an ABN have?
Eleven, the first two of which are a check on the other nine.
Does Australia have a VAT number?
No. It has the GST, and the number that appears on an invoice is the ABN. There is no separate GST number.
How do I know whether a business charges GST?
The register publishes a GST status and the date it started, separately from the ABN status. An active ABN with no GST registration is a real and common case.
Is the ABN the same as the ACN?
For a company, the ABN usually contains the nine-digit ACN with two check digits in front. Entities that are not companies have no ACN at all.
Can I download the whole Australian register for free?
Yes. The ABN Lookup bulk extract is published weekly on data.gov.au under CC-BY, with no account.
Business numbers in other countries
Last updated 8 September 2026.