Your BlackBerry's SIM card allows the network to identify you so it can direct calls to your phone. Without the SIM card, your BlackBerry phone is be recognized by your carrier, so any function relying on the carrier network does not work. The SIM card slot is located behind the battery of your phone, so you need to remove the battery before installing the SIM card.
Turn your BlackBerry off by pressing the "Power" button for several seconds.
Turn the BlackBerry over and press the battery cover release to lift off the cover.
Grasp the battery with your fingertips and pull it upward to remove it from the phone.
Locate the SIM slot. Depending on your BlackBerry model, it might be located at the bottom or top of the battery compartment.
Align the SIM card with this slot so that the metal contacts are facing down and the notched corner is away from the slot. Slide the SIM card under the plastic guide so that it lies flat.
Align the battery contacts with the contacts in the battery compartment and push the battery down into place.
Place the battery cover onto the back of the BlackBerry and push until it clicks into place.
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