@kuura/hetu-validator

A lightweight, dependency-free TypeScript library for validating Finnish Personal Identity Codes (Henkilötunnus/HETU).

Features

• Validates format, date, and checksum.
• Supports 19th, 20th, and 21st-century separators (including new 2023/2024 standards).
• Checks for leap years and future dates.
• Optional support for test/artificial IDs (900 series).
• Written in TypeScript with type definitions included.

Installation

npm install @kuura/hetu-validator
# or
yarn add @kuura/hetu-validator
# or
pnpm add @kuura/hetu-validator

Usage

import { validateFinnishHetu } from '@kuura/hetu-validator';

// Basic validation
const isValid = validateFinnishHetu('131052-308T'); 
console.log(isValid); // true

// Handling whitespace (trims by default)
validateFinnishHetu('  131052-308T  '); // true

// Validating test IDs (Artificial IDs 900-999)
validateFinnishHetu('010101-900R'); // false (default)
validateFinnishHetu('010101-900R', { allowTestIds: true }); // true

API

validateFinnishHetu(hetu, options?)

Validates a Finnish Personal Identity Code.

Parameters

• hetu (string): The HETU string to validate.
• options (object, optional):
  • allowTestIds (boolean, optional): Whether to accept artificial IDs (individual numbers 900-999). Defaults to false.
  • trimInput (boolean, optional): Whether to trim whitespace from the input string before validation. Defaults to true.

Returns

• boolean: true if the HETU is valid, false otherwise.

License

MIT