The International Mobile Equipment Identity or IMEI is a number unique to every GSM and WCDMA and iDEN mobile phone, as well as some satellite phones. It is usually found printed inside the battery compartment of the phone. It can also be displayed on the screen of the phone by entering *#06# into the keypad.

The IMEI number is used by the GSM network to identify valid devices and therefore can be used to stop a stolen phone from accessing the network.

For example, if a mobile phone is stolen, the owner can call his or her network provider and instruct them to “ban” the phone using its IMEI number. This renders the phone useless, whether or not the phone’s SIM is changed.

IMEI Number analysis