Number Validators
Check whether an ID, tax or account number is well formed, by the rules each authority publishes. Numbers are processed in your browser.
DNI, NIE & NIF Validator
Check the control letter of a Spanish DNI or NIE, or work it out from the number. Tax numbers of companies are recognised by their first letter.
TC Kimlik No Validator
Check the two check digits of an 11-digit Turkish identity number, or work them out from the first nine digits.
INN & SNILS Validator
Check the check digits of a Russian taxpayer number (ИНН, 10 or 12 digits) and of an insurance number (СНИЛС, 11 digits), and write a СНИЛС in its usual form.
CPF and CNPJ Validator
Check the check digits of a Brazilian CPF or CNPJ, including the new alphanumeric CNPJ, and see it formatted.
IBAN Validator
Check an IBAN's length, national format and check digits against the SWIFT IBAN Registry, and see it written in groups of four.
Codice Fiscale Calculator
Work out the codice fiscale from surname, name, date and place of birth, or decode a code to see the date, sex and place of birth it contains.
Choosing the right number validator
The number validators check the check digits of identity, tax and bank account numbers: the letter of a Spanish DNI or NIE, the last two digits of a Turkish T.C. Kimlik Numarası, the check digits of a Russian ИНН and СНИЛС and of a Brazilian CPF or CNPJ (including the alphanumeric CNPJ), the Italian codice fiscale, which can also be calculated from name, date and place of birth, and the length, format and check digits of an IBAN. They follow the rules published by the authorities concerned, say which parts they cannot check because no official calculation is published, and make random test numbers for development. A correct check digit only shows that a number is well formed, not that it has been issued.
These tools run in your browser, and the numbers you enter are not sent to LeedyBox or saved. Each tool page names the official source of its rules and the date it was last checked. The test numbers they make are random and meant only for software testing; never use them as real documents.
The number validator guides explain how each number is built and how its check digits are calculated, with worked examples from the official sources.