Ultrasn0w version 1.2.5 is the latest version of ultrasn0w that you can use to unlock your iPhone 4. Ultrasn0w unlock was released swiftly as iOS 5.0.1 was released and you can use this tool to unlock your iPhone 4 or iPhone 3GS.
We have compiled a short and easy tutorial for you to let you easily unlock your iPhone.
The most important step is to first determine if your iPhone is actually unlockable. This of-course is dependent upon your baseband version. If you purchased your iPhone 4 during the early days of it’s release, it’ highly likely that you have an un-lockable baseband version. Nevertheless we have listed the Basebands here that can be unlockable. If your baseband matches one of the then you are good to go.
For iPhone 4S: Currently there is no unlock for iPhone 4S With Ultrasn0w.
For iPhone 4: Version 01.59.00
For iPhone 3GS: Versions 04.26.08, 05.11.07, 05.12.01, 05.13.04, And 06.15.00
Check your baseband
Checking your baseband is really easy. Just go to settings menu from your iPhone, look for the About section and then “Modem Firmware” Tab. If yours matches any of the above, then you can easily unlock your iPhone.
Step:1 The next step is to Jailbreak your iPhone running on iOS 5.0.1
Step:2 Now all you have to do is to go to Cydia and install ultrasn0w 1.2.5. Now Let ultrasn0w do it’s work and when it reboots your phone, you would have an unlocked iPhone!
Now just change your SIM to any preferred network and it should connect to your network without any glitch.
If you need any more assistance or did not understand any step correctly, just leave a comment below.