If you have lost your mobile, have a look here http://www.immobilise.com/how_does_it_work_iframe.html .Though be aware this only works if the IMEI has not been changed and most handset IMEI can be altered quite easily. http://www.immobilise.co.uk Provider contacts to block a handset or find out if an IMEI is blocked , ( tip of the day-- Orange are central to this so a call to Orange should quickly be passed to all providers even if you are not with them ). Orange Pay as you go: 07973 100451 Contract: 07973 100150 Vodafone Pay as you go: 08700776655 Contract: 07836 191191 O2 Pay as you go: 08705 678678 Contract: 08705 214000 T-Mobile 0845 4125000 Virgin 0845 6000789 Due to the possibility of fraud the AV Forums will not allow discussion on how to unlock locked or blocked mobile phones. If you find a mobile phone our advice is to hand it in to your local police station. If you have a problem with your own locked phone please speak to your service provider.