All mobile phones have unique serial numbers. When you enter *#06#, a number 15 will appear on the screen of your mobile phone, which is the serial number of your mobile phone. Please write down this number and keep it safe. When your mobile phone is stolen, you can provide this number to your service provider, and the service provider can lock your lost mobile phone. Even if someone else replaces your original sim card, this mobile phone cannot be used. Maybe you can't get it back, but your mobile phone is of no value to them unless it is used as a paperweight. If each of us can know the unique serial number of our mobile phone, there is no point in stealing it. Please pass this message on to as many people as possible. With the popularization of this common sense, people will lose their mobile phones less and less.