CNPJ Validator
Quickly check whether a Brazilian CNPJ is valid according to the official rules of the Receita Federal (Brazil's federal tax authority), including the new alphanumeric CNPJ. Type the number in the field below and click validate to get the result instantly.
What is a CNPJ?
The CNPJ (Cadastro Nacional da Pessoa Jurídica) is the Brazilian company taxpayer ID, a unique number that identifies businesses and organizations in Brazil. It works like a "CPF for companies" and is required for any legal activity, such as issuing invoices (notas fiscais), opening bank accounts and meeting tax obligations.
How does CNPJ validation work?
A CNPJ has 14 characters, and the last two are check digits. They are calculated from the other characters with a specific algorithm (weighted sums and modulo 11). In the alphanumeric CNPJ, the first 12 positions may contain letters, and each character enters the calculation as its ASCII code minus 48. Validation means checking the number's format, recalculating the check digits and comparing them with the ones provided.
How to use
- Enter the CNPJ — With or without dots, slash and dash.
- Click Validate — The check runs automatically.
- See the result — Valid or invalid is shown instantly.
When to use this tool
- Before saving Brazilian customer or company data
- When testing form validation
- When integrating with Brazilian systems and APIs
- To catch typos
Frequently asked questions
How do I know if a CNPJ is valid?
A CNPJ is valid when its last two digits match the check digit calculation made on the first 12 characters. The validator does that math instantly.
Does the validator accept alphanumeric CNPJs?
Yes. CNPJs with letters in the first 12 positions, such as 12.ABC.345/01DE-35, are validated with the same official rule, converting each character to its ASCII code minus 48.
Does the validator show the company name?
No. The tool only checks whether the number is valid. To see registration data, look up the CNPJ registration certificate on the Receita Federal website.
Do I need to type the CNPJ with formatting?
No. You can type the CNPJ with or without dots, slash and dash.