Ontoom

CNPJ validator

Validate CNPJ check digits (with or without mask).

CNPJ

Important: Synthetic data for testing. Misuse is the user's responsibility.

Need to create a synthetic CNPJ? CNPJ generator.

How to validate CNPJ

Enter the number and validate. Ontoom checks both check digits without querying the tax authority. To generate a new test number, use the CNPJ generator.

Frequently asked questions

Does validating a CNPJ confirm the company exists?
No. The check is only of check digits and format.
Does it accept masked CNPJ?
Yes. Paste with or without punctuation; the tool normalizes the digits.
Why is my CNPJ invalid?
Wrong check digits, wrong digit count, or an invalid sequence (e.g. all identical).
Where can I generate a test CNPJ?
In Ontoom’s CNPJ generator, then come back here to validate manual entries.

See also