How to Tell If Your Apple iPhone Is Unlocked

Versions of Apple's iPhone that run on GSM networks require a SIM card that typically locks the phone to one wireless carrier. A locked phone will not work with a SIM card from another service provider. Unlocking the phone allows it to accept SIM cards from any GSM carrier. Unfortunately, using unofficial methods to unlock an iPhone is not a permanent fix and the phone may become locked again after an operating system update. You can determine whether your iPhone is unlocked using a quick and simple procedure.

Step

Insert the end of the iPhone SIM eject tool or a straightened paper clip into the small tray-eject hole on the iPhone's SIM tray. On the iPhone 4, this hole is located on the right side of the phone, near the middle. On earlier models, it is located on top of the phone, near the audio jack. Push on the SIM-eject tool or paper clip until the SIM tray ejects from the phone.

Step

Pull the SIM tray out and remove the existing SIM card. Replace it with a SIM card from another GSM network.

Step

Slide the SIM tray back into the slot, flush with the iPhone.

Step

Tap the "Phone" icon on the iPhone’s home screen and try to make a call. If the call goes through, the iPhone is unlocked.