How to Activate a 3G AT&T SIM Card

By Kefa Olang

For AT&T iPhone 3G or 3GS users, you need to activate your Subscriber Identity Module (SIM) card before you can begin using it. An AT&T SIM card is a portable memory chip. If you have inserted the SIM card in the iPhone 3G or 3GS and it is not working, it has to be activated---unlike other companies that allow you to insert the card and begin usage. Activating the AT&T iPhone 3G SIM card is actually easy because it is done automatically using iTunes.

Things You'll Need

  • iPhone 3G or 3GS
  • Supplied USB cable

Step 1

Insert the SIM card into the SIM card slot on your AT&T iPhone 3G or 3GS.

Step 2

Download and install the latest iTunes (see Resources below) if you do not already have it installed on your computer.

Step 3

Connect your iPhone 3G or 3GS to the computer using the provided USB cable. Once it has been connected, iTunes will automatically detect the iPhone 3G phone and automatically launch.

Step 4

Click "Download and Update" to update the carrier settings and activate the SIM card on the iPhone 3G. Once you finish this step, your SIM card is activated, but if you want to proceed to create an Apple account, click "Continue." Type in your name, contact information and a password to create an Apple account.