CNPJ Validator
Validate numeric and alphanumeric CNPJs in bulk and see which check digit failed.
CNPJs to check
Numeric or alphanumeric, with or without dots, slash and dash. Lowercase letters are accepted. Up to 1000 per check.
Results
Paste a CNPJ to check it as you type.
Validation runs entirely in your browser. Nothing is sent or stored. A valid result means the number is well formed, not that the company exists or is active.
Frequently asked questions
How do I validate a CNPJ?
Compute the two check digits from the first 12 characters and compare them with the last two. Multiply the characters by 5, 4, 3, 2, 9, 8, 7, 6, 5, 4, 3, 2, sum, and take the remainder of dividing by 11: 0 or 1 gives 0, otherwise 11 minus the remainder. Repeat over 13 characters with weights 6, 5, 4, 3, 2, 9, 8, 7, 6, 5, 4, 3, 2 for the second digit.
How do I validate the new alphanumeric CNPJ?
Use the same weights and mod 11 rule, but value each character as its ASCII code minus 48: digits stay 0 to 9, A is 17 and Z is 42. Uppercase the input first. The Receita Federal's own example, 12.ABC.345/01DE-35, is valid. Because the numeric CNPJ is a special case of this rule, one routine validates both formats.
When does the alphanumeric CNPJ start?
The Receita Federal set it in Instrução Normativa RFB nº 2.229/2024: new CNPJs can be alphanumeric from July 2026. Existing numeric CNPJs stay valid and do not change, so systems must accept both formats side by side.
Does a valid CNPJ mean the company exists?
No. Passing the check digit test only means the number is well formed. To confirm a company is registered and active, look it up on the Receita Federal's CNPJ inquiry service.
Why is 00.000.000/0000-00 rejected?
A sequence of one repeated character passes the check digit math by coincidence, but it is never issued. Validators reject these sequences explicitly.