Tax ID Validator

A lightweight, zero-dependency, and universal TypeScript library to validate Tax IDs (Identification Numbers)

It uses precise mathematical algorithms to verify the integrity of the document number and follow guides of the country governments

Features

• 🚀 Lightweight: Zero external dependencies.
• 🔒 Type-Safe: Written in TypeScript with full type definitions.
• 🌍 Universal: Works in Node.js, React, Vue, Next.js, and Browsers (Legacy Script Tag).
• ⚡ Tree-shakeable: Only import what you need (if using advanced exports).

Installation

npm install validator-tax-id
# or
yarn add validator-tax-id
# or
pnpm add validator-tax-id

Usage

Basic Usage

The main function validateIdentification takes two arguments: the country code (ISO 3166-1 alpha-2) and the value to validate.

import { validateIdentification } from "validator-tax-id";

// 🇪🇸 Spain (ES)
validateIdentification("es", "12345678Z"); // true (DNI)
validateIdentification("es", "X1234567L"); // true (NIE)
validateIdentification("es", "A58818501"); // true (CIF)

// 🇵🇹 Portugal (PT)
validateIdentification("pt", "232013969"); // true (NIF)

// 🇫🇷 France (FR)
validateIdentification("fr", "443061841"); // true (SIREN)

Individual Validators (Recommended) ✨

For better tree-shaking and direct access, use individual validators:

import {
  // Spain
  validateDNI,
  validateNIE,
  validateCIF,
  // France
  validateSIREN,
  validateSIRET,
  validateNIR,
  // Portugal
  validateNIF,
} from "validator-tax-id";

// 🇪🇸 Spain - Direct validation
validateDNI("12345678Z"); // true
validateNIE("X1234567L"); // true
validateCIF("A58818501"); // true

// 🇫🇷 France - Direct validation
validateSIREN("443061841"); // true
validateSIRET("44306184100047"); // true
validateNIR("188057512301180"); // true

// 🇵🇹 Portugal - Direct validation
validateNIF("123456789"); // true

Country Auto-detect

If you don't know the specific document type:

import { validateES, validateFR, validatePT } from "validator-tax-id";

validateES("12345678Z"); // true (auto-detects DNI)
validateES("A58818501"); // true (auto-detects CIF)
validateFR("443061841"); // true (auto-detects SIREN)
validatePT("123456789"); // true

API Reference

validateIdentification(country, value)

• country: CountryCode ('es' | 'pt' | 'fr') - The ISO code of the country.
• value: string | any - The document string to validate.
• Returns: boolean (true if valid, false otherwise).

Note: The validator sanitizes the input automatically (removes spaces, hyphens, and is case-insensitive).

SUPPORTED COUNTRIES

| Country | Code | Documents Supported | Algorithm | | -------- | ---- | ------------------- | ------------- | | Spain | es | DNI, NIE , CIF | Module 23 | | Portugal | pt | NIF (Personal) | Module 11 | | France | fr | SIREN, SIRET, NIR | Luhn + Mod.97 |

Changelog

All notable changes to this project will be documented in this file.

[1.2.0] - 2026-01-19

Added 🚀

• Individual Validators: New exported functions for direct validation:
  • Spain: validateDNI, validateNIE, validateCIF, validateES
  • France: validateSIREN, validateSIRET, validateNIR, validateFR
  • Portugal: validateNIF, validatePT
• Better tree-shaking support with individual exports
• Country auto-detect validators (validateES, validateFR, validatePT)

[1.1.3] - 2026-01-18

Added 🚀

• France (FR) added validation for NIR document and fix SIREN-SIRET algorithm
• Spain (ES) added validation for CIF document.
• Portugal (PT) added validation on prefix in NIF document

[1.1.0] - 2026-01-17

Added 🚀

• France (FR) support added.
• Validation for SIREN (9 digits) and SIRET (14 digits) using Luhn algorithm.

[1.0.0] - 2026-01-17

Added

• Initial release.
• Spain (ES) support: DNI and NIE validation (Modulo 23).
• Portugal (PT) support: NIF validation (Modulo 11).
• Core logic and TypeScript types.

License

MIT