# Validate an EU VAT number in Node.js

Validate an EU VAT number from Node.js or TypeScript with one fetch call to an API that asks VIES for you: no SOAP package, JSON back.

## Node.js example

    const API = "https://agent-data-tools.revmesh2074.workers.dev/vat/validate";
    
    async function checkVat(vat) {
      const r = await fetch(`${API}?${new URLSearchParams({ vat })}`, {
        headers: { Authorization: `Bearer ${process.env.API_KEY}` },
      });
      if (r.status >= 500) return null; // VIES or the member state gave no answer: try again later
      if (!r.ok) throw new Error(await r.text());
      return r.json();
    }
    
    const result = await checkVat("SE556703748501");
    if (result === null) console.log("no answer right now");
    else if (result.valid) console.log("valid:", result.name, result.address);
    else console.log("not valid");

## When an agent wants this

- Check a customer's VAT number in a checkout or sign-up form handler
- Validate VAT numbers in a serverless function
- Skip the VIES SOAP service and its WSDL

## VAT number validation, EU VIES

VAT number validation, EU VIES. $0.01 per successful call; failed calls are never charged.

Check an EU VAT number against the European Commission's VIES service: valid or not, with the registered name and address where the member state shares them. Any spacing (SE556703748501, DE 123 456 789; EL or GR for Greece, XI for Northern Ireland). Or verify a business by name: found or not in the French, Swedish, Norwegian and Finnish registers. Use to check a B2B customer before invoicing without VAT, or to confirm a supplier.

Inputs: vat: VAT number with its 2-letter EU country prefix (give vat or name); name: Company name to verify instead of a VAT number: found or not in the FR, SE, NO and FI company registers; country: With name: search only this register (FR, SE, NO or FI, or the country's name).

Free first (3 successful calls per caller, no key):

    curl "https://agent-data-tools.revmesh2074.workers.dev/vat/validate?vat=SE556703748501&trial=1"

With a card key from https://agent-data-tools.revmesh2074.workers.dev/credits, in a header or, when your client can only fetch a URL, in the URL:

    curl -H "Authorization: Bearer adt_…" "https://agent-data-tools.revmesh2074.workers.dev/vat/validate?vat=SE556703748501"
    curl "https://agent-data-tools.revmesh2074.workers.dev/vat/validate?vat=SE556703748501&api_key=adt_…"

Without a key the same URL answers 402 with x402 and MPP terms, so a wallet client pays USDC per call and retries. Over MCP (https://agent-data-tools.revmesh2074.workers.dev/mcp) this tool is vat_validate.

Example result:

    {
      "vat": "SE556703748501",
      "country": "SE",
      "number": "556703748501",
      "valid": true,
      "name": "Spotify AB",
      "address": "REGERINGSGATAN 19, 111 53 STOCKHOLM",
      "checkedAt": "2026-11-06T14:36:47.903Z",
      "source": "EU VIES (European Commission)"
    }

Tool page: https://agent-data-tools.revmesh2074.workers.dev/tools/vat-validate

## Questions

**Do I need a SOAP package?** No. The API speaks to VIES; your code sends one HTTPS GET and reads JSON.

**How should I treat an error?** As no answer, not as not valid. A 5xx means VIES or the member state could not be reached; the call is not charged and can be repeated.

Docs for agents: https://agent-data-tools.revmesh2074.workers.dev/llms.txt · OpenAPI: https://agent-data-tools.revmesh2074.workers.dev/openapi.json · All guides: https://agent-data-tools.revmesh2074.workers.dev/guides