SIM cards hold a cell phone user's account information, which allows the cell phone handset to operate on the user's cell phone service provider network. The SIM card also holds a user's phone book. Some SIM cards also hold the phone setting information, media such as photos and text messages.
Turn off the SIM-capable cell phone handset. If the SIM card that you want to read is not already in the handset, you will need to insert it into the handset. The handset must either be an unlocked cell phone or a cell phone that is on the same network that the SIM card is programmed to access.
Remove the back casing of the cell phone handset. Most phones have the SIM card slot under the battery. Lift off the backing (or just the battery depending on the cell phone model) and locate the SIM card slot. If there is already a SIM card in there, remove it by lifting up the metal holding clip and sliding the card out.
SIM cards are usually small white square shaped cards, about the size of the average human thumbnail. There is gold circuitry printed on the card as well.
Place the SIM card that you want to read into the SIM card slot. Slide the SIM card into place, ensuring that the gold circuitry printed on the SIM card lines up with the gold connector lines in the SIM card slot. Usually the card is placed face down to achieve this. Snap the holding clip back into place.
Replace the battery and the backing of the phone. Turn the cell phone back on. Wait a few seconds for the phone to access the network. If the cell phone is able to work on the network that the SIM card is associated with, the SIM card will be able to be read on the cell phone.
Access the SIM card information by using the cell phone keypad to navigate the menu. Use the phonebook menu to view the SIM card phone book and the text message menu to view any text messages. Browse the cell phone's on-screen menu such as photos and settings. Any information stored on the SIM card will be accessible if the card is compatible with the cell phone.
You can swap SIM cards with an unlocked cell phone or phone on the same network. Once the SIM card is swapped, the new cell phone handset will ring whenever someone tries to text or call the cell number associated with the SIM card. Verizon Wireless cell phone handsets do not generally use SIM cards, but most other major carriers do.