Many websites, which have been selling unlock for other devices in past, are now offering permanent unlock solution for iPhone 4 and iPhone 3GS. They use the IMEI number of iPhone and unlock the device remotely without installing any software on the device.
It is unclear which route they adopt but at the end they get added the IMEI number of the locked iPhone in the white-list of Apple’s database. So this is the third method which you can use to unlock your device and use SIM from any carrier. We will discuss all three methods in details after the break.
Method 1: Ultrasn0w
This is the most reliable method available for iPhone unlocking. As you know Ultrasnow working is based iPhone baseband. So far the following basebands (01.59.00 / 04.26.08 / 05.11.07 / 05.12.01 / 05.13.04 / 06.15.00) can be unlocked using Ultrasnow. It is to remind you that a jailbroken iPhone is required to install Ultrasnow on your device.
Unfortunately Ultrasn0w doesn’t support the latest basebands (02.10.04 / 03.10.01 / 04.10.01 / 05.14.02 / 05.15.04) and we still have no update when the next version of Ultrasnow will be released to unlock all above mentioned basebands.
Method 2: Gevey SIM
In this method you have to use a special SIM and call at 112 emergency number to get your phone activated, which might be illegal in some countries. Moreover it does not support all firmwares and basebands. You have to follow some troublesome steps on every reboot to get the signals of unsupported carrier. In contrast to Ultrasnow, you also have to pay few bucks to get it.
Method 3: IMEI Unlocking
iPhone unlocking by IMEI does not require a jailbroken device. Everything is done remotely as we have told you above and even iPhone Dev Team member has also confirmed these unlock offerings are legit.
This method supports all current firmwares and basebands but your device might be re-locked by Apple if you update to new version. The bad part of this technique is the price which is almost thrice as compared to Gevey SIM ranging between $150 $200.
Disclaimer: We won’t be responsible for any type of damage to you or your iPhone caused by using these methods. You can avail the services from above mentioned sites at your own risk and responsibility.
Update 1X: Here is a new method of unlocking the device using SAM from Cydia. It is software based unlock and free for jailbroken devices.