How to Use a Go Phone SIM Card on an iPhone

By Derek Young

The "pay as you go" Go Phone plans can often save you a lot of money over the long run if you don't use a lot of minutes. Instead of paying for AT&T's monthly plans, you can opt to only pay for as much service as you use. However, what if you want to use an iPhone? The iPhones are by default locked to only AT&T's service. To use your Go Phone SIM card with an iPhone, you'll have to first jailbreak the iPhone, which allows you to install software that unlocks your iPhone so you can use a Go Phone SIM with it.

Step 1

Google your firmware version and find a jailbreak for your iPhone. Each version of firmware and each model of iPhone requires a slightly different process to jailbreak your iPhone. Some models of the iPhone 3G and 3GS can do a one-step jailbreak right from the iPhone browser. The iPhone 4 requires a download.

Step 2

Get the Cydia Installer. Some versions of the jailbreak automatically include Cydia, while with other builds, such as quickpwn or older versions of limera1n, you need to get Cydia separately. To install Cydia, add "" as the installation source in the installer.

Step 3

Find "ultrasn0w" from the Cydia installer. Once ultrasn0w is installed, your phone will be unlocked and can be used with a Go Phone SIM card.

Step 4

Take out your SIM card by inserting a pin or unfolded paper clip into the tiny hole by the SIM tray. It's on the right side of the iPhone 4 or on the top of the iPhone 3G and 3Gs. Put your Go Phone SIM card on the tray and put it back into the phone.

Tips & Warnings

  • The iPhone 4 requires a smaller SIM than the Go Phone's standard size. You can cut your SIM with special SIM cutters purchased online. You can also cut it on your own with a knife or scissors by using your iPhone 4's default SIM as a guide for the size.