ID Number Validators and Generators
Validate and generate test numbers for 13 documents: CPF, CNPJ, CURP, RFC, RUT, NIT, CUIT, RUC, DNI/NIE, NIF, Chinese ID, TC Kimlik and NIK.
Frequently asked questions
Does a valid number mean that the person or company exists?
No. It only means the check digits are correct, which catches typing mistakes. Whether the number was actually issued, and to whom, can only be checked with the authority that issues it.
What are the generated numbers for?
For testing: filling in forms in development, testing databases and validation code. They are made at random with correct check digits, so by chance one may coincide with a real number. Never use them to identify yourself, sign up for anything or deceive anyone.
How does a check digit work?
It is calculated from the other digits with a fixed formula, usually multiplying each digit by a weight and taking the remainder of a division (modulo 11, or modulo 23 for the Spanish DNI letter). If one digit is typed wrong or two are swapped, the check digit no longer matches.
Everything happens in your browser: the numbers you type are not sent or stored.