In this paper, the authors create an application "Theft monitoring" where the users are able to find their lost phone easily. Sometimes they accidently tend to replace their phone somewhere and they end up searching for it. Hence to avoid such situations and keeping the recent demand and the greed for phones in mind they have decided to develop this application "Theft monitoring". This application gets activated as soon as the person who has stolen the phone changes the SIM and switches on the phone. The user will not know that an automatic message is being sent to the predefined number.