Information available about a phone based on its IMEI includes the manufacturer of the phone, the brand, the model, the SIM card size, the operating system and the phone's band. An IMEI check also reveals whether the device has been reported lost or stolen.
The international mobile equipment identity code, or IMEI, is unique to every mobile phone. Although the 15-digit or 17-digit code is typically printed on the battery compartment of a phone, an alternative way to get it is by dialing *#06# on the device. IMEI codes of cellphones connected to a GSM or UMTS network are stored in the equipment identity register, which is a database that contains information on all valid mobile phone equipment. When a phone is reported stolen, the IMEI is blacklisted. The phone is then rendered unusable, even if the SIM card is changed.
An IMEI code consists of four groups. The first set of numbers is the type approval code, or TAC, where the first two digits represent the country code and the rest are the final assembly code. The second set of numbers represents the manufacturer of the phone, the third set represents the serial number, and the last set, usually a zero, is an additional number.