Provided by: libalgorithm-checkdigits-perl_0.50-1_all #### NAME

```       CheckDigits::M11_011 - compute check digits for VAT Registration Number (NL)

```

#### SYNOPSIS

```         use Algorithm::CheckDigits;

\$ustid = CheckDigits('ustid_nl');

if (\$ustid->is_valid('123456782')) {
# do something
}
if (\$ustid->is_valid('123456782B04')) {
# do something
}

\$cn = \$ustid->complete('12345678');
# \$cn = '123456782'
\$cn = \$ustid->complete('12345678.B04');
# \$cn = '123456782B04'

\$cd = \$ustid->checkdigit('123456782');
# \$cd = '2'
\$cd = \$ustid->checkdigit('123456782B04');
# \$cd = '2'

\$bn = \$ustid->basenumber('123456782');
# \$bn = '12345678';
\$bn = \$ustid->basenumber('123456782B04');
# \$bn = '12345678.B04';

```

#### DESCRIPTION

```       This VATRN has 12 "digits", the third last must be a B, the fourth last is the checkdigit.
I don't know anything about the meaning of the last two digits.

You may use the whole VATRN or only the first eight digits to compute the checkdigit with
this module.

ALGORITHM
1.  Beginning right with the digit before the checkdigit all digits are weighted with
their position. I.e. the digit before the checkdigit is multiplied with 2, the next
with 3 and so on.

2.  The weighted digits are added.

3.  The sum from step 2 is taken modulo 11.

4.  If the sum from step 3 is 10, the number is discarded.

METHODS
is_valid(\$number)
Returns true only if \$number consists solely of numbers and hyphens and the two digits
in the middle are valid check digits according to the algorithm given above.

Returns false otherwise,

complete(\$number)
The check digit for \$number is computed and inserted into the middle 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.

```

#### SEEALSO

```       perl, CheckDigits, www.pruefziffernberechnung.de,

```

#### AUTHOR

```       Mathias Weidner, <mathias@weidner.in-bad-schmiedeberg.de>

```

```       Copyright 2004,2005 by Mathias Weidner