How do I validate a Spanish NIF or CIF via API?

Call GET https://developers.autonomo-simple.es/api/validate-nif?value=B12345674. It returns JSON with valid, type and entity type. No API key required.

Yes. The fiscal validators are free with no API key, and the documented government APIs are public open-data services.

Developer platform · Open data

Spanish Tax & Government APIs.

The largest collection of public APIs, fiscal validators and administrative services for Spain. Build accounting, invoicing, ERP, SaaS and compliance software faster.

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8Government APIs

4Fiscal validators

0€No API key

JSONFirst-class

Quick start

Copy-paste examples for the most common tasks. The validator endpoints are free, need no key, and are CORS-open so you can call them from the browser.

Validate a Spanish VAT number (NIF/CIF)

Check the control digit of any NIF, NIE or CIF — free, no API key.

fetch("https://developers.autonomo-simple.es/api/validate-nif?value=B12345674")
  .then((res) => res.json())
  .then(console.log);
// { value: "B12345674", valid: true, type: "CIF", entityType: "Sociedad Limitada", ... }

Check an EU VAT number (VIES)

Verify an intra-community VAT number against the European Commission VIES service.

fetch("https://ec.europa.eu/taxation_customs/vies/rest-api/ms/ES/vat/A58818501")
  .then((res) => res.json())
  .then(console.log);
// { isValid: true, name: "...", address: "..." }

Get ECB euro exchange rates

The official euro reference rates the AEAT uses — daily, from the European Central Bank.

fetch("https://data-api.ecb.europa.eu/service/data/EXR/D.USD.EUR.SP00.A?lastNObservations=1&format=jsondata")
  .then((res) => res.json())
  .then(console.log);

Search Spanish public grants (BDNS)

Query every public subsidy convened in Spain from the national grants database.

fetch("https://www.infosubvenciones.es/bdnstrans/api/convocatorias/busqueda?page=0&pageSize=10")
  .then((res) => res.json())
  .then(console.log);

Fiscal validators

Control-digit checks running locally — no network, no key, nothing leaves your browser. The same algorithms back the public /api/validate-* endpoints. ✓ Verified June 2026

NIF · NIE · CIF validator

Control-digit check (mod-23) + entity type. Mirrors GET /api/validate-nif.

Try:

Enter an identifier to validate it

IBAN validator

MOD-97 checksum (ISO 13616), any country. Mirrors GET /api/validate-iban.

Try:

Enter an IBAN to validate it

Tax identity & VAT

Validate intra-community operators and EU VAT numbers.

VIESEuropean Commission

Official✓ Verified Jun 2026

Validate an EU intra-community VAT number and get the registered name/address. Essential for invoicing EU businesses under the reverse-charge mechanism.

Auth: None
Format: JSON
Status: ● Active

GET https://ec.europa.eu/taxation_customs/vies/rest-api/ms/{cc}/vat/{nif}

Official docs →