How to get the letter of the DNI

Have you ever needed to know the letter of your ID and you did not remember it? Have you ever wondered what the letter that accompanies the digits means ? Well it is not random, but it is a mathematical calculation result of a simple logarithm that you can solve yourself. In this article we give you the steps to follow to obtain the letter of the DNI.

Steps to follow:


To obtain the letter of your identity document, you must take the 8 digits that make up your ID number.

Example: 12345678


Divide that number by 23.

Example: 12345678/23 = 536768


Take the rest of the division (it will not be exact), which should be a number between 0 and 22.

Example: the rest is 14


Find in this table which letter corresponds to the number obtained.

Example: a 14 corresponds to the Z


You will already have your ID number with the letter that you have.

Example: 12345678Z