If you need the serial number off a Subscription Identity Module, or SIM card, to prove ownership of your phone, the number can be found quite easily. SIM cards hold valuable information, such as text messages and telephone numbers. A SIM card is also portable and can be transferred from one phone to another of the same compatibility.
Power down your cellular device and wait until the power is completely off. Remove the battery cover from the back of the phone by sliding it out of place.
Grab one end of the battery and lift and pull it until it clicks out of place. Remove the battery from its holster.
Grab one end of the SIM card, located directly beneath the battery holster, and pull up until it clicks out of place. Remove it from the phone and inspect it until you find the serial number. The SIM card is very small and it will be impossible to miss the prominent serial number.