table of contents
Algorithm::CheckDigits::M23_002(3pm) | User Contributed Perl Documentation | Algorithm::CheckDigits::M23_002(3pm) |
NAME¶
CheckDigits::M23_002 - compute check digits for Tax Identification Number (IE)
SYNOPSIS¶
use Algorithm::CheckDigits; $dni = CheckDigits('tin_ie'); if ($dni->is_valid('8473625E')) { # do something } $cn = $dni->complete('1234567.W'); # $cn = '1234567TW' $cd = $dni->checkdigit('1234577IA'); # $cd = 'I' $bn = $dni->basenumber('1234577WW'); # $bn = '1234577.W'
DESCRIPTION¶
ALGORITHM¶
The irish TIN (Tax Identification Number) or VAT Regstration Number consists of 7 digits, a letter in the range from 'A' - 'W' as checksum, and an optionally letter in the range from 'A' - 'I' or the letter 'W'.
- 1.
- In reverse order, each digit is multiplied by a weight started at 2. (i.e. the number left from the check digit is multiplied with 2, the next with 3 and so on).
- 2.
- If there is an optional letter following the checksum letter (position 9), this letter is mapped to a numeric value based on the following mapping: "A" = 1, "B" = 2, ... "H" = 8, "I" = 9. "W" or absence of this letter means a value of 0. This numeric value is multiplied with 9.
- 3.
- All products from step 1 and 2 are added.
- 4.
- The check digit is the sum from step 3 modulo 23. This number is expressed as the corresponding letter from the alphabet where A-V correspond to 1-22 and W stands for check digit 0.
METHODS¶
- is_valid($number)
- Returns true only if $number complies with the
rules given above and there is a valid check digit at position eight.
Returns false otherwise,
- complete($number)
- The check digit for $number is computed and
inserted at position eight of $number.
Returns the complete number with check digit or '' if $number does not consist solely of digits and an optional letter at position nine.
- basenumber($number)
- Returns the basenumber of $number if
$number has a valid check digit. As a placeholder
for the checksum a point ('.') is inserted at position eight when the
checksum contains the optional letter at position nine.
Return '' otherwise.
- checkdigit($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, https://ec.europa.eu/taxation_customs/tin/
2021-11-17 | perl v5.40.0 |