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VAT / GST / ABN Number Validator

Check one number or upload a CSV with up to 100. We hit the authoritative registries — EU VIES, UK HMRC, Norway Brønnøysund — and return the registered name and address when available.

Accepts formatted or unformatted IDs. Country prefix is optional.

Registry coverage

Live registry lookup (returns business name + address):

EU — VIES
All 27 member states · authoritative
United Kingdom — HMRC
VAT check service · authoritative
Norway — Brønnøysund
Enhetsregisteret · authoritative

Format-only validation (regex check, no registry hit):

Switzerland (CHE)
MWST / TVA / IVA format
Australia (ABN)
11-digit format
Japan (JCT)
T + 13 digits
Singapore (GST)
UEN format
Canada (GST/HST)
BN + RT format
India (GSTIN)
15-char format
Korea
3-2-5 format

Need this at scale or inside your invoicing flow?

Sign up for a free DeterminedAI account to get an API key, unlimited validations, webhook callbacks, and VIES/HMRC results cached for 24 hours.

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About the VAT, GST & ABN Number Validator

DeterminedAI's free tax-ID validator is the fastest way to check whether a VAT number, GST registration, or ABN is currently valid against the authoritative public registry. Single lookups return in under a second; bulk validation through CSV upload handles up to 100 numbers per request without an account, and unlimited volumes via the DeterminedAI API.

Unlike scrapers or screenshot bookmarks, every check goes directly to the registry of record — VIES for the 27 EU member states, HMRC for the United Kingdom, Brønnøysund Enhetsregisteret for Norway, BrasilAPI for Brazilian CNPJs, and the Australian Business Register for ABNs. The response includes the registry-published trader name and address where available, plus a request reference you can store as audit evidence.

Common use cases

How it works

Pick a country, paste the VAT or GST number with or without the country prefix, and hit Validate. The tool normalises the format, calls the appropriate registry, and returns a structured response with valid, name, address, checked_at, and a registry-issued request_id when one is provided. For batch and CSV modes, every row is processed in parallel with built-in retries for transient registry errors. Format-only countries (Switzerland, Japan, Singapore, Canada, India, Korea) get a regex check that confirms the structure is correct — useful for catching typos before submission to local authorities.

Related guides

Frequently asked questions

How do I validate an EU VAT number?

Enter the country prefix and number (for example DE123456789) into the validator above. We query the European Commission's VIES (VAT Information Exchange System) in real time and return whether the number is currently registered, plus the trader name and address when the member state publishes them.

VIES is the only authoritative source for cross-border EU VAT verification — keep the response as evidence that you applied the reverse charge correctly.

Can I validate VAT numbers in bulk?

Yes. Upload a CSV with up to 100 numbers, or paste a list into the batch tab. Each row is checked against the appropriate registry and you can download enriched results as CSV with status, registered name, and address.

There is no sign-up or rate limit for the public tool. Customers with API keys can validate unlimited numbers programmatically with 24-hour caching.

Why does a VAT number show as invalid in VIES but valid in the local registry?

VIES only confirms that a VAT number is valid for intra-EU transactions. Some member states issue domestic VAT numbers that aren't enabled in VIES — common in Germany (Steuernummer without USt-IdNr.), Spain (NIF without ROI registration), and Italy (no VIES opt-in).

For domestic supplies the local registration is fine, but for B2B reverse charge under Article 138 the buyer's number must be VIES-valid at the time of supply. Always store the VIES response payload as evidence.

Do I need to validate the VAT number on every invoice?

Best practice is to validate at customer onboarding, then re-validate periodically — quarterly or before each high-value invoice.

EU case law (notably Mecsek-Gabona) holds the supplier liable for VAT if the buyer's number was invalid when the supply was made and the supplier didn't take reasonable steps to verify it. The VIES request ID returned in our response is recognised by tax authorities as proof of the check.

Which countries does the validator cover?

Authoritative registry checks: all 27 EU member states (VIES), the United Kingdom (HMRC), Norway (Brønnøysund Enhetsregisteret), Brazil (BrasilAPI for CNPJ), Australia (ABR for ABN).

Format-only checks (regex): Switzerland CHE/MWST, Japan JCT, Singapore GST, Canada GST/HST, India GSTIN, South Korea. These confirm the structure is correct but don't hit a live registry — useful for catching typos before submission.

Is this tool free?

Yes. The web validator is free and unlimited with no account required. We rate-limit only at the IP level to prevent abuse.

If you need to run validations from your own application, sign up for a free DeterminedAI account to get an API key with 500 calls per month included; paid plans bump this to 25,000+ calls and add webhook callbacks.