What is a Spanish NIF-IVA number?

It is the ES prefix followed by a 9-character NIF or CIF. Individuals use a DNI (8 digits + letter) or NIE (X/Y/Z + 7 digits + letter); companies use a CIF (letter + 7 digits + control).

How is the DNI control letter calculated?

Take the 8-digit number modulo 23 and index into the table TRWAGMYFPDXBNJZSQVHLCKE. The resulting letter must match the final character. NIE numbers map X to 0, Y to 1, Z to 2 first.

How does the CIF check digit work?

Digits in odd positions are doubled and digit-summed, even positions are added directly, the units of the total are subtracted from 10, and that gives a control digit or its letter form depending on the entity-type letter.

Does a valid result mean the company is VAT-registered?

No. A valid result only confirms the number is internally consistent. To confirm active VAT registration for intra-EU trade you must query the EU VIES service.

Is my VAT number sent anywhere?

No. All format and check-character logic runs locally in your browser, so the number never leaves your device.

Spain VAT Number Validator

A Spanish VAT number (Número de Identificación Fiscal a efectos del IVA, or NIF-IVA) is the ES prefix followed by a 9-character tax identifier. Unlike many EU countries, Spain reuses its national identifiers — the DNI for residents, the NIE for foreigners, and the CIF for legal entities — as the body of the VAT number. This validator detects which structure you have entered and recomputes the official control character so you can catch typos before submitting an invoice or a VIES lookup.

How it works

There are three valid structures behind the ES prefix:

DNI (individuals): 8 digits plus a control letter. The letter is TRWAGMYFPDXBNJZSQVHLCKE indexed by number mod 23.
NIE (foreign residents): a leading X, Y or Z, 7 digits, and a control letter. Map X to 0, Y to 1, Z to 2, then apply the same mod-23 rule.
CIF (entities): an entity-type letter, 7 digits, and a control character. Digits in odd positions are doubled and digit-summed, even positions are added directly; the control is (10 - units) mod 10, expressed as a digit or as a letter from JABCDEFGHI depending on the entity type.

Example

For the DNI body 12345678Z, compute 12345678 mod 23 = 14, and the 15th character (0-indexed 14) of TRWAGMYFPDXBNJZSQVHLCKE is Z. The control letter matches, so ES12345678Z is internally valid.

Notes

A valid check character means the identifier is well-formed, not that the entity is currently VAT-registered. For real-time confirmation in intra-EU transactions, query the official EU VIES system. This tool performs no network lookup — everything is computed in your browser.