---
name: "Algorithm::CheckDigits::M11_008"
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_008"
---

# Algorithm::CheckDigits::M11\_008(3pm)

compute check digits for VAT Registration Number (DK)

## NAME

CheckDigits::M11\_008 - compute check digits for VAT Registration Number (DK)

## SYNOPSIS

```
  use Algorithm::CheckDigits;
  $ustid = CheckDigits('ustid_dk');
  if ($ustid->is_valid('13585628')) {
        # do something
  }
  $cn = $ustid->complete('1358562');
  # $cn = '13585628'
  $cd = $ustid->checkdigit('13585628');
  # $cd = '8'
  $bn = $ustid->basenumber('13585628');
  # $bn = '1358562';
```

## DESCRIPTION

### ALGORITHM

- 1\.

  Beginning left every digit is weighted with 2, 7, 6, 5, 4, 3, 2, 1

- 2\.

  The weighted digits are added.

- 3\.

  The sum from step 2 is taken modulo 11.

- 4\.

  The number is valid if the sum from step 3 is zero (0).

### METHODS

- is\_valid($number)

  Returns true only if `$number` consists solely of numbers and the sum computed according to the algorithm given above is 0.

  Returns false otherwise,

- complete($number)

  Returns `$number` if `$number` is valid according to the algorithm given above.

  Return '' otherwise.

- basenumber($number)

  Returns `$number` if `$number` is valid according to the algorithm given above.

  Return '' otherwise.

- checkdigit($number)

  Returns '' if `$number` is valid.

  Return undef otherwise.

### EXPORT

None by default.

## AUTHOR

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

## SEE ALSO

perl, CheckDigits, *www.pruefziffernberechnung.de*,