NAME

Business::BR::CNPJ - Perl module to test for correct CNPJ numbers

SYNOPSIS

use Business::BR::CNPJ; 

print "ok " if test_cnpj('90.117.749/7654-80'); # prints 'ok '
print "bad " unless test_cnpj('88.222.111/0001-10'); # prints 'bad '

DESCRIPTION

The CNPJ number is an identification number of Brazilian companies emitted by the Brazilian Ministry of Revenue, which is called "Ministério da Fazenda".

CNPJ stands for "Cadastro Nacional de Pessoa Jurídica" (literally, national juridical person registration) as opposed to the CPF number for natural persons. Sometime ago, it was called CGC ("Cadastro Geral de Contribuinte" or general taxpayer registration).

The CNPJ is comprised of a base of 8 digits, a 4-digits radical and 2 check digits. It is usually written like '11.111.111/0001-55' so as to be more human-readable.

This module provides test_cnpj for checking that a CNPJ number is correct. Here a correct CNPJ number means

• it is 14 digits long

• it satisfies the two check equations mentioned below

Before checking, any non-digit letter is stripped, making it easy to test formatted entries like '11.111.111/0001-55' and entries with extra blanks like ' 11.111.111/0001-55 '.

test_cnpj

test_cnpj('999.444.333-55') # incorrect CPF, returns 0
test_cnpj(' 263.946.533-30 ') # is ok, returns 1
test_cnpj('888') # nope, returns undef

Tests whether a CNPJ number is correct. Before testing, any non-digit character is stripped. Then it is expected to be 14 digits long and to satisfy two check equations which validate the last two check digits. See "THE CHECK EQUATIONS".

The policy to get rid of '.', '/' and '-' is very liberal. It indeeds discards anything that is not a digit (0, 1, ..., 9). That is handy for discarding spaces as well.

test_cpf(' 263.946.533-30 ') # is ok, returns 1

But extraneous inputs like '#333%444*2a3s2z~00' are also accepted. If you are worried about this kind of input, just check against a regex:

warn "bad CPF: only digits (14) expected" 
  unless ($cpf =~ /^\d{14}$/);

warn "bad CPF: does not match mask '__.___.___/____-__'" 
  unless ($cpf =~ /^\d{2}\.\d{3}\.\d{3}/\d{4}-\d{2}$/);

NOTE. Integer numbers like 9999811299 (or 99_998_112_99) with fewer than 14 digits will be normalized (eg. to 99_999_999_9999_99) before testing.

flatten_cnpj

flatten_cnpj(99); # returns '00000000099'
flatten_cnpj('999.999.999-99'); # returns '99999999999'

Flattens a candidate for a CNPJ number. In case, the argument is an integer, it is formatted to at least fourteen digits. Otherwise, it is stripped of any non-digit characters and returned as it is.

format_cnpj

format_cnpj('00 000 000 0000 00'); # returns '00.000.000/0000-00'

Formats its input into '00.000.000/0000-00' mask. First, the argument is flattened and then dots, slash and hyphen are added to the first 14 digits of the result.

parse_cnpj

($base, $filial, $dv) = parse_cnpj($cpf);
$hashref = parse_cnpj('11.222.333/4444-00'); # { base => '11222333', filial => '4444' dv => '00' }

Splits a candidate for CNPJ number into base, radical and check digits (dv - dígitos de verificação). It flattens the argument before splitting it into 8-, 4- and 2-digits parts. In a list context, returns a three-element list with the base, the radical and the check digits. In a scalar context, returns a hash ref with keys 'base', 'filial' and 'dv' and associated values.

EXPORT

test_cnpj is exported by default. flatten_cnpj, format_cnpj, and parse_cnpj can be exported on demand.

THE CHECK EQUATIONS

A correct CNPJ number has two check digits which are computed from the 12 first digits. Consider the CNPJ number written as 14 digits

c[1] c[2] c[3] c[4] c[5] c[6] c[7] c[8] c[9] c[10] c[11] c[12] dv[1] dv[2]

To check whether a CNPJ is correct or not, it has to satisfy the check equations:

5*c[1]+4*c[2]+3*c[3]+2*c[4]+9*c[5]+
8*c[6]+7*c[7]+6*c[8]+5*c[9]+4*c[10]+
                    3*c[11]+2*c[12]+dv[1] = 0 (mod 11) or
                                          = 1 (mod 11) (if dv[1]=0)

and

6*c[1]+5*c[2]+4*c[3]+3*c[4]+2*c[5]+
9*c[6]+8*c[7]+7*c[8]+6*c[9]+5*c[10]+
            4*c[11]+3*c[12]+2*dv[1]+dv[2] = 0 (mod 11) or
                                          = 1 (mod 11) (if dv[2]=0)

BUGS

I heard that there are exceptions of CNPJ numbers which don't obey the check equations and are still authentic. I have never found one of them.

SEE ALSO

To make sure this module works, one can try the results obtained against those found with "Emissão de Comprovante de Inscrição e de Situação Cadastral de Pessoa Jurídica", a web page which the Brazilian Ministry of Revenue provides for public consultation on regularity status of the taxpayer. This page tells if the CNPJ number is a correct entry (14-digits-long with verified check digits), if it references a real company and if it is regular with the government body.

Given a bad CNPJ, the after-submit page tells "O número do CNPJ não é válido" (the CNPJ number is not valid). If the CNPJ is a good one but does not reference a real company, it says "CNPJ não existe em nossa base de dados" (CNPJ does not exist in our database). Otherwise, it shows a details form for the identified taxpayer.

Note that this module only tests correctness. It doesn't enter the merit whether the CNPJ number actually exists at the Brazilian government databases.

As you might have guessed, this is not the first Perl module to approach this kind of functionality. Take a look at

http://search.cpan.org/search?module=Brasil::Checar::CGC

Please reports bugs via CPAN RT, http://rt.cpan.org/NoAuth/Bugs.html?Dist=biz-br By doing so, the author will receive your reports and patches, as well as the problem and solutions will be documented.

AUTHOR

A. R. Ferreira, <ferreira@cpan.org>

COPYRIGHT AND LICENSE

Copyright (C) 2005 by A. R. Ferreira

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.6 or, at your option, any later version of Perl 5 you may have available.

cpanm Business::BR

perl -MCPAN -e shell
install Business::BR