IMEI validator and check digit calculator

How the IMEI check digit works

The 15th digit of an IMEI is calculated from the first 14 with the Luhn algorithm, the same method used for payment card numbers. It exists to catch typing errors, not to prove a number is genuine.

1. Starting from the left, double every second digit (the 2nd, 4th, 6th and so on).
2. If doubling gives a two-digit number, add its digits together (for example 14 becomes 1 + 4 = 5).
3. Add up all fourteen resulting digits.
4. The check digit is the amount needed to reach the next multiple of ten.

Valid does not mean genuine

A correct check digit only means the number is well formed. Counterfeit phones often carry well-formed IMEIs copied from real devices. To learn which model an IMEI belongs to and whether it is locked, run the full check on the homepage.

Frequently asked questions