How is an IMEI validated?

The 15th digit is a Luhn check digit over the first 14. Doubling every second digit from the right, subtracting 9 where the result exceeds 9, and summing all digits including the check digit must produce a total divisible by 10.

What is the TAC in an IMEI?

The TAC (Type Allocation Code) is the first 8 digits and identifies the device model and manufacturer. The next 6 digits are the device serial, and the 15th is the Luhn check digit.

Does a valid IMEI mean the phone is not stolen?

No. A passing Luhn check only confirms the number is well-formed. Whether a device is blacklisted or reported stolen requires a carrier or GSMA database lookup, which this tool does not perform.

My IMEI has 16 digits, why?

A 16-digit value is an IMEISV, which appends a 2-digit software version. Drop the final two digits to get the 15-digit IMEI this validator expects.

Is my IMEI sent anywhere?

No. The Luhn calculation runs entirely in your browser, so your IMEI never leaves your device.

IMEI Number Validator

An IMEI (International Mobile Equipment Identity) is the 15-digit number that uniquely identifies a mobile phone or cellular modem. The final digit is a Luhn check digit, the same algorithm credit cards use, which lets you catch typos. This free validator runs that check locally and breaks the IMEI into its structural parts.

How it works

The IMEI’s 15th digit is a Luhn checksum over the first 14:

Write out the 15 digits.
Walking from the right, double every second digit. If a doubled value exceeds 9, subtract 9 from it.
Add up all the resulting values, including the unchanged check digit.
The IMEI is valid if that total is divisible by 10.

The tool also separates the TAC (first 8 digits — the Type Allocation Code identifying the model and manufacturer) and the 6-digit serial.

Example

For 490154203237518, applying Luhn to all 15 digits yields a sum divisible by 10, so the IMEI is valid. The TAC is 49015420 and the serial is 323751. If you mistype a digit, the Luhn sum no longer ends in 0 and the IMEI is rejected; the tool then shows the correct check digit for the first 14 digits so you can spot the error.

A valid checksum only confirms the format — it does not check blacklist status. All processing is local to your browser.