Brazil CNPJ Validator

Brazil CNPJ validator (mod-11)

The CNPJ (Cadastro Nacional da Pessoa Jurídica) is Brazil’s company taxpayer number: 12 base digits followed by 2 mod-11 check digits. This validator recomputes both check digits, rejects reserved all-identical sequences, and shows the formatted number — useful for form validation and data cleaning.

How it works

The tool strips punctuation and confirms 14 digits. It computes the first check digit from a weighted sum of the 12 base digits (weights 5,4,3,2,9,8,7,6,5,4,3,2), and the second from the 12 base digits plus the first check digit (weights 6,5,4,3,2,9,8,7,6,5,4,3,2). For each:

remainder = sum mod 11; digit = remainder < 2 ? 0 : 11 − remainder

If both computed digits match the printed ones — and the number is not 14 identical digits — the CNPJ is valid.

Example

For 11.222.333/0001-81:

• Base = 112223330001
• First check digit computes to 8
• Second check digit computes to 1
• Both match → Valid CNPJ

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