EU VAT number validation API (VIES)

Short answer: To validate an EU VAT number programmatically, call GET https://api.wsystem.dev/verify?vat=IE6388047V. It queries the European Commission's VIES service and returns status (valid, invalid, invalid_format, member_state_unavailable or error), the registered name and address where the member state discloses them, and a VIES consultation number as audit proof. No signup or API key is needed for 20 calls per day per IP.

Key facts

Covers all 27 EU member states plus Northern Ireland (XI). Greece uses the prefix EL, not GR.
Source: VIES, run by the European Commission. W System is an independent wrapper and is not affiliated with the Commission.
Input is normalised: spaces, dots and dashes are removed, so DE 811 193 231 works.
Batch: POST /verify/batch takes up to 100 numbers per request.
When a national database is offline, the API retries with backoff, then falls back to an official national source (PL, CZ, FI, FR) or the last successful VIES result, flagged fallback: true with source and legal_status and no consultation number. Otherwise it returns member_state_unavailable with valid: null, never a false invalid. Details: VIES down fallback.
UK: GB numbers are accepted and check-digit validated; live validation through the HMRC Check a UK VAT number API v2 is built but needs HMRC Developer Hub OAuth credentials, which are not configured yet, so GB results currently return status: not_configured. Northern Ireland (XI) numbers are checked in VIES.
Free tools: bulk VAT checker for CSV files and live VIES status.
Consultation number: pass your own EU VAT number as requester (default is ours) to get a dated VIES reference you can keep for audits.
Germany and Spain usually do not disclose name/address through VIES; validity is still returned.

Examples

Validate one VAT number

curl "https://api.wsystem.dev/verify?vat=IE6388047V"

Real response (live data, 2026-10-17):

{
 "input": "IE6388047V",
 "vat": "IE6388047V",
 "country_code": "IE",
 "vat_number": "6388047V",
 "status": "valid",
 "valid": true,
 "name": "GOOGLE IRELAND LIMITED",
 "address": "3RD FLOOR, GORDON HOUSE, BARROW STREET, DUBLIN 4",
 "request_date": "2026-10-17T06:07:32.092Z",
 "consultation_number": "WAPIAAAAaFIeQCDg",
 "requester": "HU33119856",
 "source": "VIES (European Commission)",
 "cached": true
}

German number (no name/address disclosed by DE)

curl "https://api.wsystem.dev/verify?vat=DE811193231"

Real response (live data, 2026-10-17):

{
 "input": "DE 811 193 231",
 "vat": "DE811193231",
 "country_code": "DE",
 "vat_number": "811193231",
 "status": "valid",
 "valid": true,
 "name": null,
 "address": null,
 "request_date": "2026-10-17T06:07:30.845Z",
 "consultation_number": "WAPIAAAAaFIePvTH",
 "requester": "HU33119856",
 "source": "VIES (European Commission)",
 "cached": true
}

Batch of up to 100

curl -X POST https://api.wsystem.dev/verify/batch -H 'Content-Type: application/json' \
  -d '{"vats":["IE6388047V","FR40303265045"],"requester":"YOUR_EU_VAT"}'

Pricing

Channel	Price
Website checker, REST and MCP free tier	Free, 20 calls/day per IP, no key
x402 REST: GET /verify	$0.01 USDC per call
x402 REST: POST /verify/batch (up to 100)	$0.10 USDC per request
Apify Actor wsystem/eu-vat-checker	$0.005 per VAT checked + $0.005 per run

Comparison with alternatives

	W System API	VIES REST/SOAP (EC, direct)	vatlayer (apilayer)
Free usage	20 calls/day per IP, no key	Free, no key	100 requests/month, non-commercial, signup + key
Paid entry price	$0.01 per call (x402), no subscription	n/a (free)	$9.99/month for 1,000 requests
Batch endpoint	Yes, 100 per request	No (one number per call)	Not listed on pricing page
MCP server for AI agents	Yes, remote, 7 tools	No	Not listed
Pay per call without account (x402)	Yes, USDC on Base	No	No (card subscription)
Consultation number (audit proof)	Yes, with requester VAT	Yes, with requester VAT	Not listed
EORI, registry, sanctions in same API	Yes	No	VAT rates and price calculation instead

Based on each provider's public pages on 2026-10-17. Corrections welcome via GitHub issues.

Questions and answers

Is there a free EU VAT validation API without an API key?

Yes. The VIES REST API itself is free, and W System's api.wsystem.dev gives 20 free calls per day per IP with no key and no signup, adding batch, retries, caching and an MCP endpoint.

How do I check a VAT number for reverse charge?

Validate the customer's VAT number with GET /verify on the invoice date and keep the consultation_number from the response as evidence. A valid VIES result is one of the conditions for zero-rating intra-EU B2B supplies; it is not tax advice.

What does member_state_unavailable mean?

The member state's national database behind VIES did not answer (MS_UNAVAILABLE). The number is not invalid. Retry later; the API already retries with backoff before returning this.

Why is name and address empty for a German VAT number?

Germany (and often Spain) do not publish name/address through VIES. The validity result is still official.

Can I validate UK VAT numbers?

GB numbers are not in VIES since Brexit. The API accepts GB numbers and checks the HMRC check digits, and has HMRC Check a UK VAT number API v2 support built in, but that needs OAuth app credentials from the HMRC Developer Hub which are not configured yet; until then GB results say not_configured. XI (Northern Ireland) numbers are fully checked in VIES.

Can AI agents use it?

Yes. Connect any MCP client to https://api.wsystem.dev/mcp/ and use the verify_vat or verify_batch tools.

Facts and competitor details checked 2026-10-17. W System Hungary Kft. is the maker of this product. Not affiliated with the European Commission. Not legal or tax advice.