IMEI
The IMEI is the 15-digit identity of a handset or module. It names the device, not the SIM inside it.
Definitions only — a term explained here is not a service we sell.
The international mobile equipment identity names one physical device, independent of the SIM inside it. The first eight digits, the TAC, name the model; the rest name the unit.
Several countries register the IMEI alongside the line for theft control. The rules differ, so a device legal in one market may be restricted in another.
IMEI structure
Decoded in your browser. Nothing is uploaded.
- TAC (model)
- 35693803
- Serial
- 564380
- Check digit
- 9
Text description
The example is synthetic. The first eight digits are the type allocation code, then six serial digits and a Luhn check digit. Typed input stays in the browser.
Model and unit
The TAC identifies the model, and the GSMA assigns it. The check digit catches transcription errors, not clones. The IMEISV is 16 digits and replaces the check digit with a two-digit software version, so record the two separately. The four numbers explainer shows where the IMEI sits.
Why it matters
A SIM swap does not change the IMEI, and neither does an eSIM download. That makes it useful for inventory and theft control. The device sends it during attach, but the network may not retain or forward it. Rewriting an IMEI is usually illegal and always a fraud signal.