CNPJ Validator
Quickly and easily validate your CNPJ! Our CNPJ validator ensures the authenticity of the provided number, confirming that it is valid and error-free. If you need to generate a new CNPJ, try our CNPJ generator.
How CNPJ Validation Works
What does the validator check?
The CNPJ validator checks the mathematical consistency of the 2 check digits using the official Receita Federal algorithm with specific weights and modulus 11. It does not query the Receita Federal CNPJ database, does not verify if the company exists, is active, or has a regular status. Validation only confirms that the format and verifiers are mathematically correct for the 12 informed base digits.
When is a CNPJ considered invalid?
A CNPJ is invalid when: (1) it has fewer or more than 14 digits; (2) all digits are the same (e.g. 11.111.111/1111-11); (3) the check digits do not match the calculation of weights applied to the 12 base digits. When you type a CNPJ in the validator, any of these conditions is automatically checked and the result is displayed immediately.
Why use CNPJ validators in development?
Invoice issuing systems, ERPs, B2B e-commerce platforms, and supplier registrations need to validate CNPJ before processing any data. The Help4Dev validator is useful for testing whether the validation logic implemented in the system is correct, as well as manually verifying whether a specific CNPJ is mathematically valid during application development and debugging.