Australia VAT number: format and validation

By Remco from Avatcado

Format

AU followed by 11 digits (the ABN). The local term is Australian Business Number (ABN, English).

Pattern: /^\d{11}$/

  • Australia levies GST (goods and services tax), not VAT; the ABN is the identifier used for it
  • Holding an ABN does not imply GST registration; ABN Lookup shows a separate GST registration date

Example of a registered number: 51 824 753 556

Check digit

Australia VAT numbers carry a check digit (MOD 89): Subtract 1 from the first digit, multiply the 11 digits by the weights 10,1,3,5,7,9,11,13,15,17,19, and the ABN is valid if the sum is divisible by 89.

Check a Australia VAT number

Validated live against the Australian Business Register (ABN Lookup) (official register).

Enter a VAT number to see the live API response

Validate via API

The same validation as an API call, with the example number above:

curl "https://api.avatcado.com/v1/validate?vat_number=AU51824753556" \
  -H "Authorization: Bearer avat_live_your_api_key"
import Avatcado from "@avatcado/node";

const avatcado = new Avatcado("avat_live_your_api_key");
const { data, error } = await avatcado.vat.validate({
  vatNumber: "AU51824753556",
});

if (data?.data.valid) {
  console.log(`Registered: ${data.data.company?.name}`);
}

Free tier includes 500 validations per month. Get an API key or read the API documentation.

Frequently asked questions

Is an ABN the same as being GST-registered?

No: every Australian business needs an ABN, but GST registration is a separate step required from AUD 75,000 annual turnover (AUD 150,000 for not-for-profits). An ABN can be active with no GST registration.

How do I check whether an ABN is GST-registered?

Look it up on ABN Lookup (abr.business.gov.au): the entry shows the ABN status and the date GST registration started, or omits the GST line entirely if the business is not registered.

Related guides

VAT rate in Australia

The standard VAT rate in Australia is 10%. See all Australia VAT rates.

Sources