To remove the SIM card from your iPhone, you'll need to eject the SIM card tray with a special tool or paperclip.

The subscriber identity module -- SIM -- contains the information used to connect to your wireless carrier's network from your iPhone 4. If you are planning to resell your company's iPhones, you ...

You can check to see if your iPhone is unlocked from a carrier using any of a few different methods.

The iPhone Air will only have an eSim - will other phone makers also shift away from the familiar - but fiddly - plastic ...