---
name: "Algorithm::CheckDigits::M10_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::M10_008"
---

# Algorithm::CheckDigits::M10\_008(3pm)

compute check digits for Sedol (GB)

## NAME

CheckDigits::M10\_008 - compute check digits for Sedol (GB)

## SYNOPSIS

```
  use Algorithm::CheckDigits;
  $sedol = CheckDigits('sedol');
  if ($sedol->is_valid('0123457')) {
        # do something
  }
  $cn = $sedol->complete('012345');
  # $cn = '0123457'
  $cd = $sedol->checkdigit('0123457');
  # $cd = '7'
  $bn = $sedol->basenumber('0123457');
  # $bn = '012345'
```

## DESCRIPTION

Prior to March 2004 SEDOL codes solely consisted of numbers. Since March 2004 SEDOL codes are a 7 character alphanumeric code.

The structure of the alphanumeric SEDOL codes is one alpha character followed by 5 alphanumeric characters followed by the numerical check digit.

- Alpha characters are B-Z excluding vowels.

  - Alphanumerical characters are 0-9, B-Z excluding vowels.

  - Numerical Characters are 0-9.

  No SEDOL code will be issued without the first alpha character. Active numerical SEDOL codes issued prior to March 2004 remain valid.

### ALGORITHM

- 0

  All characters are assigned a numerical value from 0 to 35 where the characters '0' to '9' get 0 to 9, 'B' to 'Z' get 11 to 35 with the position of the vowels kept empty (for instance 'D' gets 13, 'F' gets 15).

- 1

  Beginning left all numbers are weighted with 1,3,1,7,3,9 and 1 (checkdigit)

- 2

  The sum of all products is computed.

- 3

  The check digit is the difference of the sum from step 3 to the next multiple of 10.

### METHODS

- is\_valid($number)

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

  Returns false otherwise,

- complete($number)

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

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

  This function always returns the SEDOL code in upper case.

- basenumber($number)

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

  Return '' otherwise.

  This function always returns the SEDOL base number in upper case.

- checkdigit($number)

  Returns the checkdigit 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, *www.londonstockexchange.com* Masterfile technical specifications V7.0.