A SIM card is a smart card inserted into your cellular phone that links it to your cellular account on your network. The network then allows your phone to make calls. A SIM card can store some personal information. There are a number of reasons why you might need a new SIM card for your AT&T service. You may have lost your phone, and may need to reactivate an older phone until you can buy a new one. Or you may be buying a new phone. You can retain your current phone number when the new SIM card is activated.
Use an Older Phone
Go to an AT&T wireless retail outlet to buy a new SIM card. These cards range in price from about $5 to $12.
Insert the SIM card in your old phone.
Test your new SIM card. Place a call to a friend or family member to see if your old cell phone works with your newly bought SIM card. Ask the friend if your old phone number appears on their caller ID.
Use a New Phone
Buy a new phone. Search for phones that you like at AT&T retail stores near your home and choose the phone that best meets your needs.
Let a store representative know that you want to keep your prior cellular phone number. The rep will then do all of the work to migrate your number to your new phone.
Test your new phone. Call a close friend or family member to see if your phone works correctly. Also, ask them if they see your number appear on their caller ID, to make sure you still have the same cell phone number.
Things You'll Need
New SIM card
Old cell phone