IMEI Validator
Verify the check digit of a 15-digit IMEI and read the type allocation code that identifies the device model.
How this tool works
An IMEI is a 15 or 16 digit number identifying a mobile device's radio hardware, and it is structured: the first eight digits are the Type Allocation Identifier, which identifies the model, and the last two are the check digits. The checksum is the Luhn algorithm over the first fourteen digits.
Validation is therefore a length check, a digit check and a Luhn check. Beyond that, the TAI can be resolved against the issuing body to give the manufacturer and the model, and the serial number within it identifies the individual unit. The check digit exists because IMEIs are read from stickers and typed by hand.
Worked example
| Step | Value |
|---|---|
| IMEI | 490154203237518 |
| TAI | 49015420 |
| Serial | 32375 |
| Check digits | 18 |
| Result | Valid, the Luhn checksum over the first 14 digits passes |
The check digit is the last one of the pair. On a 16 digit IMEI the final digit is the check digit and the fifteenth is a version digit.
When to use it
- Check an IMEI for a typing error before a device enrolment
- Validate device records in an inventory system
- Confirm that a device identifier matches the expected model
- Find a transcription error in a list of IMEIs
Frequently asked questions
What is an IMEI?
A 15 or 16 digit identifier for a device's radio hardware, made up of a Type Allocation Identifier identifying the model, a serial number and a check digit.
How is an IMEI checked?
The length must be 15 or 16, all characters must be digits, and the final digit must match the Luhn checksum over the preceding digits.
What is the TAI?
The Type Allocation Identifier: the first eight digits, which identify the manufacturer and the model and are assigned by the issuing body.
Does a valid IMEI mean the device is activated or genuine?
No. It means the number is internally consistent. Whether the device is genuine, unlocked, blacklisted or active is a question for the network and the device's own records.
Why do some IMEIs have 16 digits?
The sixteenth is a version digit, used when a device gets a new software version that changes its hardware identity. Most devices still have 15.
Can I find the manufacturer from an IMEI?
Yes, from the first eight digits, which are the Type Allocation Identifier and are allocated per model.