IMEI
The 15-digit number that identifies one mobile phone, its serial number on mobile networks.
IMEI stands for International Mobile Equipment Identity. Every phone has one (dual-SIM phones have two), shown by dialling *#06#, in the settings and on the box. The first 8 digits identify the model; the last one is a check digit.
For a phone reseller, the IMEI is the serial number: it says exactly which unit was bought, sold, repaired or returned. Recording it when phones arrive and on every sale is what lets you answer when a phone comes back under warranty or is reported stolen.
