Mobile phone owners are being urged to log details of their handsets on a national police register to crack down on thefts.
The public can register their mobile phones online
Thames Valley Police has joined a national mobile database to help trace owners of stolen phones.
Almost 10,000 mobile phones were stolen in Berkshire last year with more than 4,000 stolen in Oxfordshire.
If they find phones they believe are stolen, police can check the database and return the equipment to the owners.
Det Sgt Ian Holt said: "This database will help us quickly see if someone has a stolen phone with them, particularly when checking suspects' property where a robbery or burglary has taken place or long afterwards if someone is tempted to buy a stolen phone."
The Mobile Equipment National Database allows police to search registered stolen or lost phones against the unique IMEI or phone number.
The public can also register other items free on www.menduk.org, including laptops, personal organisers and cameras.
The 15-digit IMEI number can be found by keying *#06# into the phone.