Updated February 10, 2017 Find out what your cell phone’s ESN number is by looking it up on your handset. Sometimes the original box of the phone will show this number, but you can always find it by looking through your phone’s menu. The numbers start with the letters ESN. Turn off your phone and take off the battery cover and take out the battery. You should be able to see the ESN number underneath the battery. Write down this number and keep it in a safe place. If your phone is ever stolen, you can call your cell phone company and tell them to deactivate your ESN so nobody else can use your phone. If the thief tries to activate the phone and it has a GPS on it, the company can sometimes track down the person making the request and let the police know its whereabouts. Call your service provider to verify an ESN if you want to buy a phone online. They will tell you whether the phone you want to buy was reported stolen or can be used on your account. Writer Bio
