IMEI
15-digit unique device ID used by carriers to authorize service and to block stolen phones. Find it via Settings → About, or by dialing *#06#.
The IMEI (International Mobile Equipment Identity) is a 15-digit number that uniquely identifies your phone hardware. Every cellular device gets one at the factory.
How to find it
- On any phone: Dial
*#06#from the Phone app. The IMEI shows on screen instantly. - iPhone: Settings → General → About → IMEI. Also on the SIM tray (eject with a paperclip).
- Android: Settings → About phone → IMEI / Status.
- Original box: The IMEI is printed on the box label.
What carriers use IMEI for
- Activation eligibility. When you switch carriers, the new carrier checks your IMEI against its compatibility list and a stolen-device blacklist.
- Stolen-phone blocking. If you report a phone stolen, carriers blacklist its IMEI so it can't be activated on any US carrier.
- Insurance + financing. Apple, Samsung, and carrier financing programs use IMEI to track which device you bought.
If you're buying a used phone
Get the IMEI from the seller and run it through swappa.com's ESN check or your target carrier's "bring your own device" check page before paying. A blacklisted IMEI is essentially worthless — you can't activate it on any major US carrier.