Jailbreaking is not a cup of tea for everyone. For some people it is a tough nut to crack. Locked iPhones are “unlocked” by jailbreaking. Apple does sell unlocked iPhones and other devices but they are more expensive than the locked once.
However, in the present context, “unlocking a device” means that you can activate it on other wireless carriers outside of the one you purchased your phone from.
Following tutorial lists the steps that can help you in unlocking your iPhone 4S without jailbreaking. This tutorial describes the procedure to unlock an AT&T iPhone 4S that works on T-Mobile’s network. Results on other carriers may vary. For this procedure, you need a GSM iPhone 4S, and both an AT&T and T-Mobile SIM card. Or you can also get a SIM card that is from a compatible GSM carrier.
STEP 1 – Insert your AT&T SIM card.
STEP 2 – Dial 611 for customer care service and hang up when it starts ringing.
STEP 3 – Turn on the Airplane mode of your iPhone. Take out your AT&T SIM card and replace it with T-Mobile SIM.
STEP 4 – Make sure Wi-Fi is off. Clear any remembered networks to ensure that it does get auto-connected later.
STEP 5 – Turn of the Airplane mode. The handset will search for a network and moments later, “Activation Required” screen would pop up.
STEP 6 – After noticing that your device has found an EDGE Network (E symbol), wait for at least 30 seconds before you turn of the phone.
STEP 7 – Once you notice that you have 1 bar of signal, tap on the “Use Cellular Connection” option. Eject SIM card after that.
STEP 8 – “Activation Required” should pop up again. Insert your T-Mobile SIM card again. Your iPhone 4S is unlocked now.
Some users had to repeat this process multiple times to make it work. We expect to find and report something important about this new discovery in near future.
Source: iDownload Blog