For UK members if your mobile phone is lost or stolen, call your network operator. Your phone will be blocked just like a stolen credit card.
PLEASE NOTE THAT REPORTING YOUR PHONE AS LOST OR STOLEN ON IMMOBILISE PUTS THE PHONE ON THE NATIONAL POLICE STOLEN PHONE REGISTER - IT DOES NOT BLOCK THE PHONE'S IMEI NUMBER OR SIM CARD, TO DO THIS YOU MUST CONTACT YOUR NETWORK.
Be prepared to answer some security questions to enable your Network to establish that you are the rightful owner of the phone that is being reported lost or stolen. You can find contact information for your phone network by visiting their company websites and going to their 'Contact Us' pages.
EE (Orange / T-Mobile)
After reporting your phone to your network you should also log in to your Immobilise account to flag your phone as lost or stolen, this then displays the information on the National Police Database of stolen and lost property. If you were the subject of a crime you should also contact your local police station, or the police station nearest to where the theft or loss took place, and inform them of what happened. They will assist you and provide the required references for insurance claims etc.
If you have mobile phone insurance, you should also contact your insurance provider to report any loss or theft.