How to Swap AT&T Phones
All AT&T phones contain a small microchip known as a SIM card. The SIM card authenticates the phone to the AT&T network. Swapping AT&T phones is a simple process that involves moving the SIM card from one phone to the other.
Locate the SIM card in your phone. Depending on the model of your phone, the SIM card is probably located underneath the battery in the back panel of the phone. The Apple iPhone has a hidden removable panel along the top of the phone that holds the SIM card.
Remove the SIM card from your current phone. Again, for most phones, you have to remove the back panel to access the SIM card. Remove the battery carefully and set it aside. Use your fingertips and gently slide the SIM card from its housing area.If you have an Apple iPhone, you will need a paper clip to remove your SIM card. Look along the top of your iPhone for a circular panel with a small pinhole in it. Press the paper clip into the pin hole firmly until the SIM panel pops up. Remove the panel and slide the SIM card out gently.
Insert the SIM card into your new AT&T phone. Be sure to properly insert the SIM card into its housing area. Pay close attention to the clipped corner of the SIM card and align this corner with the clipped corner of the SIM card housing area of your phone.
Replace the battery and back panel of your phone. If you have an Apple iPhone, simply replace the SIM card panel by inserting it back into your phone.
Turn on your new phone and ensure that it is able to make phone calls. If your phone does not display your information and appears unable to make phone calls, check to make sure you inserted the SIM card in the right direction.