Business::IBAN - Validate and generate IBANs

  use Business::IBAN;
  use Locale::Country;
  my $cc = country2code('Germany');
  my $iban = Business::IBAN->new();

  # ---------- generate
  my $ib = $iban->getIBAN(
  {
    ISO => $cc, # or "DE", etc.
    BIC => 12345678, # Bank Identifier Code, meaning the BLZ
                     # in Germany
    AC => "1234567890",
  });
  # or
  my $ib = $iban->getIBAN(
  {
    ISO => "DE",
    BBAN => 123456781234567890,
  });
  if ($ib) {
    print "IBAN is $ib\n";
  }
  else {
    $iban->printError();
    # or
    my @errors = $iban->getError();
    # print your own error messages (for description of error-
    # codes see section ERROR-CODES
  }

  # ------------ validate
  if ($iban->valid($ib)) {
    # note: this also accepts IBANs in paper format with spaces added
    print "$ib is valid\n";
  }
  else {
    $iban->printError();
  }

	0: No Country or Iso-Code supplied
	1: No BBAN (Bank-Number) or Bank Identifier and Accountnumber supplied
	2: Could not find country
	3: IBAN must contain two-letter ISO-Code at the beginning
	4: IBAN must only contain only alphanumerics after the ISO-code
	5: IBAN is invalid

package Business::IBAN;

require 5.005_62;
use Math::BigInt;
use strict;
use vars qw($VERSION @errors);

$VERSION = '0.06';

# error codes
use constant IBAN_CTR => 0;
use constant IBAN_BBAN => 1;
use constant IBAN_ISO => 2;
use constant IBAN_FORMAT => 3;
use constant IBAN_FORMAT2 => 4;
use constant IBAN_INVALID => 5;

sub new {
    my ($class) = @_;
    my $self = {};
    bless $self, $class;
    return $self;
} ## end sub new
# --------------------------------------
sub getIBAN {
    my ($self, $args) = @_;
	my $iso = uc $args->{ISO};
	my $bban = $args->{BBAN};
	my $bic = $args->{BIC};
	my $ac = $args->{AC};
	delete $self->{ERRORS};
	push @{$self->{ERRORS}}, IBAN_CTR unless $iso ;
	push @{$self->{ERRORS}}, IBAN_BBAN unless $bban || ($bic && $ac);
	return if $self->{ERRORS};
	$iso =~ tr/A-Za-z//cd if $iso;
	$bban =~ tr/A-Za-z09//cd if $bban;
	$ac =~ tr/A-Za-z09//cd if $ac;

	return unless $iso;
	$iso = uc $iso;
	$args->{CV} = $iso;
	$args->{CV} =~ s/([A-Z])/(ord $1)-55/eg;
	my $no;
	$args->{ISO} = $iso;
	for ($iso) {
		m/^DE$/ and $no = $self->iban_de($args), last;
		$no = $self->iban_unspec($args);
	}
	return $no;
}
# --------------------------------------
sub iban_de {
	my $self = shift;
	my $args = shift;
	$args->{BBAN} ||= sprintf "%08s%010s", $args->{BIC},$args->{AC};
	my $no = sprintf "%018s%4s00", $args->{BBAN}, $args->{CV};
	my $tmp = $no % 97;
	my $bigint = Math::BigInt->new($no);
	my $mod = sprintf "%2d", 98 - ($bigint % 97);
	substr($no,-6,6) = "";
	$no = 'IBAN '.$args->{ISO}.$mod.$no;
	return $no;
}
# --------------------------------------
sub iban_unspec {
	my $self = shift;
	my $args = shift;
	push @{$self->{ERRORS}}, IBAN_BBAN unless $args->{BBAN};
	return if $self->{ERRORS};
	my $no = sprintf "%s%4s00", $args->{BBAN}, $args->{CV};
	my $bigint = Math::BigInt->new($no);
	my $mod = 98 - ($bigint % 97);
	substr($no,-6,6) = "";
	$no = 'IBAN '.$args->{ISO}.$mod.$no;
	return $no;
}
# --------------------------------------
sub getError {
	return unless $_[0]->{ERRORS};
	return @{$_[0]->{ERRORS}};
}
# --------------------------------------
sub printError {
	return unless $_[0]->{ERRORS};
	print "$errors[$_]\n" for @{$_[0]->{ERRORS}};
}
# --------------------------------------
sub country {
	return $_[0]->{COUNTRY};
}
# --------------------------------------
sub valid {
    my ($self, $ib) = @_;
	delete $self->{ERRORS};
	# remove spaces
	$ib =~ tr/ //d;
	# invalid characters
	#(push @{$self->{ERRORS}}, IBAN_FORMAT2), return if $ib =~ tr/A-Za-z0-9//c;
	$ib =~ s/^IBAN//i;
	push @{$self->{ERRORS}}, IBAN_FORMAT unless $ib =~ m/^[A-Z][A-Z]/i;
	return if $self->{ERRORS};
	my $iso = substr $ib, 0, 2, "";
	$iso =~ s/([A-Z])/(ord $1)-55/eg;
	my $check = substr $ib, 0, 2, "";
	# convert alpha characters to their ascii code
	$ib =~ s/([A-Z])/(ord $1)-55/eg;
	# iban still contains characters which are not numbers!
	(push @{$self->{ERRORS}}, IBAN_FORMAT2), return if $ib =~ tr/0-9//c;
	$ib .= "$iso$check";
	$ib = Math::BigInt->new($ib);
	push @{$self->{ERRORS}}, IBAN_INVALID and return unless ($ib % 97)==1;
	return 1;
}
# --------------------------------------

@errors = (
	"No Country or Iso-Code supplied",
	"No BBAN (Bank-Number) or Bank Identifier and Accountnumber supplied",
	"Could not find country",
	"IBAN must contain two-letter ISO-Code at the beginning",
	"IBAN must only contain only alphanumerics after the ISO-code",
	"IBAN is invalid",
);

1;
__END__