stdnum/src/pl/nip.ts

Standard Number Validation

/**
 * NIP (Numer Identyfikacji Podatkowej, Polish VAT number).
 *
 * The NIP (Numer Identyfikacji Podatkowej) number consists of 10 digit with
 * a straightforward weighted checksum.
 *
 * Source
 *   https://www.oecd.org/tax/automatic-exchange/crs-implementation-and-assistance/tax-identification-numbers/Poland-TIN.pdf
 *
 * ENTITY
 */

import * as exceptions from '../exceptions';
import { strings } from '../util';
import { Validator, ValidateReturn } from '../types';
import { weightedSum } from '../util/checksum';

function clean(input: string): ReturnType<typeof strings.cleanUnicode> {
  return strings.cleanUnicode(input, ' -', 'PL');
}

const impl: Validator = {
  name: 'Polish VAT Number',
  localName: 'Numer Identyfikacji Podatkowej',
  abbreviation: 'NIP',
  compact(input: string): string {
    const [value, err] = clean(input);

    if (err) {
      throw err;
    }

    return value;
  },

  format(input: string): string {
    const [value] = clean(input);

    return value;
  },

  validate(input: string): ValidateReturn {
    const [value, error] = clean(input);

    if (error) {
      return { isValid: false, error };
    }
    if (value.length !== 10) {
      return { isValid: false, error: new exceptions.InvalidLength() };
    }
    if (!strings.isdigits(value)) {
      return { isValid: false, error: new exceptions.InvalidFormat() };
    }

    const sum = weightedSum(value, {
      weights: [6, 5, 7, 2, 3, 4, 5, 6, 7, -1],
      modulus: 11,
    });

    if (sum !== 0) {
      return { isValid: false, error: new exceptions.InvalidChecksum() };
    }

    return {
      isValid: true,
      compact: value,
      isIndividual: false,
      isCompany: true,
    };
  },
};

export const { name, localName, abbreviation, validate, format, compact } =
  impl;