Business::BR::CNPJ(3) Perl module to test for correct CNPJ numbers


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 '


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

CNPJ stands for ``Cadastro Nacional de Pessoa Juridica'' (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 ' 43.337.004 / 0001-72 '.

  test_cnpj('48.999.764/0001-60') # incorrect CPF, returns 0
  test_cnpj(' 43.337.004/0001-72 ') # 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) or letter. That is handy for discarding spaces as well.

  test_cnpj(' 66.818.021/0001-27 ') # is ok, returns 1

But extraneous inputs like 'a53##045%4-20**0001!50' are also accepted. If you are worried about this kind of input, just check against a regex:

  warn "bad CNPJ: only digits (14) expected" 
    unless ($cnpj =~ /^\d{14}$/);
  warn "bad CNPJ: does not match mask '__.___.___/____-__'" 
    unless ($cnpj =~ /^\d{2}\.\d{3}\.\d{3}/\d{4}-\d{2}$/);

NOTE. Integer numbers like 3337004000158 (or 3_337_004_0001_58) with fewer than 14 digits will be normalized (eg. to 03_337_004_0001_58) before testing.

  canon_cnpj(1); # returns '00000000000001'
  canon_cnpj('99.999.222/0001-12'); # returns '99999222000112'

Canon's 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-alphanumeric characters and returned as it is.

  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 canon'ed and then dots, slash and hyphen are added to the first 14 digits of the result.

  ($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 - digitos de verificaca~o). It canon's 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.

  $rand_cnpj = random_cnpj($valid);
  $good_cnpj = random_cnpj();
  $cnpj = random_cnpj(1); # also a good one
  $bad_cnpj = random_cnpj(0); # bad CNPJ

Generates a random CNPJ. If $valid is omitted or 1, it is guaranteed to be correct. If $valid is 0, it is guaranteed to be incorrect. This function is intented for mass test. (Use it wisely.)

The implementation is: generate a 8-digits random number for the base, and the variation is chosen 95% of the time to be '0001' and the other 5% a skewed random distribution with the expression "int(sqr rand(1E8))" is used. A uniform distribution is expected from "rand". With the base and variation, the check digits are computed. If $valid==0, the check digits are computed not to satisfy the check equations.


"test_cnpj" is exported by default. "canon_cnpj", "format_cnpj", "parse_cnpj" and "random_cnpj" can be exported on demand.


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:

                      3*c[11]+2*c[12]+dv[1] = 0 (mod 11) or
                                            = 1 (mod 11) (if dv[1]=0)


              4*c[11]+3*c[12]+2*dv[1]+dv[2] = 0 (mod 11) or
                                            = 1 (mod 11) (if dv[2]=0)


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.


A. R. Ferreira, <[email protected]>


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.