DNI and NIE Letter Validator (Spain)

Validate a Spanish DNI or NIE, calculate the letter of any DNI number, and generate valid DNIs and NIEs for testing. Free and in your browser.

Generate test numbers
Generated numbers are fictitious and only for testing software and forms. Using them to pass yourself off as someone, open accounts or register anything is illegal.
What it does
The Spanish DNI has eight digits and a control letter: the number divided by 23 leaves a remainder from 0 to 22, which picks the letter from the sequence TRWAGMYFPDXBNJZSQVHLCKE. The NIE, for foreign residents, starts with X, Y or Z, which count as 0, 1 and 2 for the same calculation. Type the eight digits with any letter and the page tells you the right one.
Everything happens in your browser: the numbers you type are not sent or stored.
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.
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