---
name: "Algorithm::CheckDigits::M11_016"
section: "3pm"
platform: "linux"
package: "libalgorithm-checkdigits-perl"
version: "1.3.6-2"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/Algorithm::CheckDigits::M11_016"
---

# Algorithm::CheckDigits::M11\_016(3pm)

compute check digits vor VAT Registration Number (PL)

## NAME

CheckDigits::M11\_016 - compute check digits vor VAT Registration Number (PL)

## SYNOPSIS

```
  use Algorithm::CheckDigits;
  $nip = CheckDigits('nip');
  if ($nip->is_valid('8567346215')) {
        # do something
  }
  $cn = $nip->complete('856734621');
  # $cn = '8567346215'
  $cd = $nip->checkdigit('856734621');
  # $cd = '5'
  $bn = $nip->basenumber('8567346215');
  # $bn = '856734621';
```

## DESCRIPTION

### ALGORITHM

- 1\.

  Beginning left every digit is weighted with 6, 5, 7, 2, 3, 4, 5, 6, 7

- 2\.

  The weighted digits are added.

- 3\.

  The sum from step 2 is taken modulo 11.

- 4\.

  The checkdigit is 11 minus the sum from step 3. Is the difference 10, the number won't be taken. If the difference is 11, the checkdigit is 0.

### METHODS

- is\_valid($number)

  Returns true only if `$number` consists solely of numbers and the rightmost digit is a valid check digit according to the algorithm given above.

  Returns false otherwise,

- complete($number)

  The check digit for `$number` is computed and appended to the end of `$number`.

  Returns the complete number with check digit or '' if `$number` does not consist solely of digits, hyphens and spaces.

- basenumber($number)

  Returns the basenumber of `$number` if `$number` has a valid check digit.

  Return '' otherwise.

- checkdigit($number)

  Returns the check digits of `$number` if `$number` has valid check digits.

  Return '' otherwise.

### EXPORT

None by default.

## AUTHOR

Mathias Weidner, `"<mamawe@cpan.org>"`

## SEE ALSO

perl, CheckDigits, *www.pruefziffernberechnung.de*, *http://www.pruefziffernberechnung.de/U/USt-IdNr.shtml#PZPL* (German), *http://wipos.p.lodz.pl/zylla/ut/translation.html#PZPL* (English), *http://wipos.p.lodz.pl/zylla/ut/nip-rego.html* (Polish)