Now unlocking iPhone 4 and 3GS on iOS 5.0.1 is possible. You can follow the instructions below.
Ultrasn0w is a tweak available on Cydia which is used to unlock iPhone. Unlocking your iPhone will allow you to use it with other SIM from other carrier. It is very common to purchase a cheaper iPhone with contract from any carrier but they will simply lock it with their network so you can’t use it with others.
Anyway you can unlock your iPhone with Ultrasn0w from Cydia.
Only these baseband can be unlocked:
Done? follow our guide below:
Step 1: Launch “Cydia” > tab on “Manage” > tab on “Source” > tab on “Edit” on the top right corner then tab on “Add” on the top left corner.
Step 2: Add repository source for Ultrasn0w. The source is “http://repo666.ultrasn0w.com” then you can select on “Add Source”.
Step 3: Now Cydia will start adding source. After the source was successfully added, you select on “Search” on the bottom corner right then enter the keyword Ultrasn0w.
Step 4: Click on the “Ultrasn0w” in the search result and tab on “Install” on the top corner right. Cydia will start installing the “Ultrasn0w”.
Congratulation now your iPhone is successfully unlocked. Enjoy with SIM-free iPhone.