---
name: "Algorithm::CheckDigits::M97_001"
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::M97_001"
---

# Algorithm::CheckDigits::M97\_001(3pm)

compute check digits for VAT Registration Number (BE)

## NAME

CheckDigits::M97\_001 - compute check digits for VAT Registration Number (BE)

## SYNOPSIS

```
  use Algorithm::CheckDigits;
  $ustid = CheckDigits('ustid_be');
  if ($ustid->is_valid('136695962')) {
        # do something
  }
  $cn = $ustid->complete('1366959');
  # $cn = '136695962'
  $cd = $ustid->checkdigit('136695962');
  # $cd = '62'
  $bn = $ustid->basenumber('136695962');
  # $bn = '1366959'
```

## DESCRIPTION

### ALGORITHM

- 1\.

  The whole number (without checksum) is taken modulo 97.

- 2\.

  The checksum is difference of the remainder from step 1 to 97.

### METHODS

- is\_valid($number)

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

  A leading 'BE' before the numbers will be ignored.

  Returns false otherwise,

- complete($number)

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

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

  A leading 'BE' before the digits is ignored for the computation and retained for the result.

- basenumber($number)

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

  A leading 'BE' before the digits will be ignored and not returned with the result.

  Return '' otherwise.

- checkdigit($number)

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

  Return '' otherwise.

### EXPORT

None by default.

## AUTHOR

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

## SEE ALSO

perl, CheckDigits, \<http://www.pruefziffernberechnung.de\>. \<https://en.wikipedia.org/wiki/VAT\_identification\_number\>