ABN Lookup Tool

Look up Australian Business Numbers (ABN) and verify GST registration status for any business.

Data stays on your deviceATO sourced data

Look up any Australian Business Number (ABN) to verify a business is registered and check their GST status. Enter a business name or ABN below to calculate GST amounts.

Visit abr.business.gov.au for official ABN lookups
All businesses with turnover above $75,000 must have an ABN and register for GST
An ABN is required to issue tax invoices
Check ABN status before paying invoices to ensure the business is genuine

Enter ABN to Validate

Invoice & Payment Helper

Invoice Amount (incl. GST if applicable)

Supplier provided an ABNSupplier is GST registered

About ABN Validation

This tool validates ABN format using the official ATO check digit algorithm. A valid format means the number is mathematically correct — to verify it belongs to a real, active business, use the official ABR lookup link above.

An ABN (Australian Business Number) is an 11-digit identifier. All businesses with annual turnover above $75,000 must register for GST. When paying a supplier without an ABN, you must withhold 47% of the payment.

Disclaimer

This calculator provides estimates for general information purposes only. Results should not be relied upon as professional financial, tax, or legal advice. Tax rates and thresholds are based on publicly available ATO data and may change. Always consult a qualified tax agent or financial adviser for advice specific to your circumstances.

Frequently Asked Questions

What is an ABN and do I need one?

An Australian Business Number (ABN) is an 11-digit identifier for businesses. You need an ABN if you carry on a business in Australia, whether as a sole trader, partnership, company, or trust. You also need one to register for GST, claim GST credits, or avoid having 47% withheld from payments to you.

What happens if a supplier doesn't have an ABN?

If a supplier doesn't quote an ABN on their invoice, you are generally required to withhold 47% of the payment and remit it to the ATO. This is known as 'no ABN withholding.' Exceptions apply for payments under $75, domestic services, or suppliers who have provided a Statement by Supplier form.

What is ABN Lookup Tool?

An ABN (Australian Business Number) is an 11-digit identifier issued to businesses operating in Australia. ABN lookup verifies that a business is legitimately registered and checks whether they are registered for GST.

How this calculator works

Use this GST calculator alongside the official ABN Lookup (abr.business.gov.au) to verify business registrations and calculate GST amounts for invoicing. All businesses with an annual turnover of $75,000 or more ($150,000 for non-profits) must register for GST and charge 10% on taxable supplies. When paying a supplier, always verify their ABN — if they don't provide one, you may need to withhold 47% from the payment under the no-ABN withholding rules. A valid tax invoice must include the supplier's ABN, the GST amount, and be issued within 28 days.

All calculations are performed in your browser — your data never leaves your device. Results are for general guidance only and should not be considered professional financial advice.

Built and maintained by Konstantin Iakovlev. Data sourced from the ATO and official Australian government sources.

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