Check and Validate
Free validators for IBAN, VAT, card, ID, and ISBN numbers. No sign-up needed.
A set of focused tools for checking the numbers behind bank accounts, cards, tax records, identity documents, and books. They cover the IBAN, UK VAT numbers, credit card numbers, the Spanish DNI and NIE, UK driving licences, the Romanian CNP, and the ISBN. Each one runs entirely on this page, uses the official algorithm, and explains what it found. There is nothing to install and no account to create.
Validators
European IBAN Validator
Validate an IBAN with the mod-97 checksum and the official per-country length, and see exactly which check failed.
UK VAT Number Validator
Check a UK VAT number with the HMRC modulus-97 check digit algorithm, including the newer 9755 variant.
Credit Card Number Validator
Check whether a card number is mathematically valid with the Luhn algorithm and see its likely network. Nothing is ever sent anywhere.
Spanish DNI/NIE Calculator
Work out the check letter for a Spanish DNI or NIE, or confirm whether the letter on an existing document is correct.
UK Driving Licence Decoder
Decode the date of birth and sex embedded in a 16-character UK driving licence number, and check its structure.
Romanian CNP Validator
Check the structure and control digit of a Romanian CNP, and read back the birth date, sex, and county it encodes.
ISBN Validator
Validate an ISBN-10 or ISBN-13 check digit, and convert a valid ISBN-10 into its ISBN-13 form.
This site is available in English, Romanian, and Spanish. Use the language links in the header to switch, and you will land on the same tool in the language you choose.