Every GSM mobile phone has its own unique IMEI number but most people are not aware of it and thus, their phones cannot be blocked if lost or stolen. The number is usually found printed on or underneath the phone’s battery and warranty card. In order to find out the IMEI number, the mobile owner can dial the sequence *#06# from their phone.
The GSM network uses the IMEI number to identify valid devices and also to stop a stolen phone from accessing the network. Once the phone is blocked, it is rendered useless even if the SIM card in it is changed.
Published in The Express Tribune, May 20th, 2012.