Carrier Unlock for iPhone

As promised, the iPhone Dev-Team has released the carrier unlocking tool called Ultrasn0w for US based iPhone 4 users who are stuck with AT&T network. For those of you who don’t know, carrier unlock for US iPhone 4s required complete rewrite ofultrasn0w software because of the new baseband OS present in iPhone 4.

Since Apple is selling unlocked iPhone 4s internationally, it is only the United States users who are still locked on AT&T network. So if you want to use your new iPhone 4 on networks other than AT&T, like T-Mobile for example, you can use this newly released Ultrasn0w 1.0 software to unlock your phone.

Simply follow the instructions posted below to unlock your iPhone 4 on iOS 4.0.1 / 4.0 on 01.59.00 baseband.

NOTE: T-Mobile US users will have to disable 3G by navigation to: Settings->General->Network and turning the "Enable 3G" switch to OFF before installing the ultrasn0w unlock.

How to: Jailbreak iPhone 4 on iOS 4.0.1:
Step 1: Unlocking requires that your phone is jailbroken on the latest firmware. Follow the complete guide posted here to jailbreak your iPhone 4 on iOS 4.0.1 / 4.0 usingJailbreakMe 2.0.

How to: Unlock iPhone 4 (Any Baseband) on iOS 4.0.1: 
Step 2: Once you are done with the jailbreak, you can now unlock your iPhone on any baseband using Ultrasn0w 1.0-1 from Cydia. To do this:

• Start “Cydia” on your iPhone.
• Touch on “Manage” tab on the bottom.
• Now touch on “Sources” as seen in the screenshot below:

• Touch on “Edit” and then on “Add”. You will be prompted to enter a url source as seen in the screenshot below. Type “http://repo666.ultrasn0w.com” and touch on“Add Source” to add this repo if you haven’t already.

Cydia will now automatically update your sources by following a series of automated steps.

• After installation is completed. Search for “ultrasn0w 1.0-1” in Cydia and install this application. This app will automatically unlock your iPhone so that you can use it with any carrier.

Step 3: Now simply restart your iPhone and voila! you should now have a fully unlocked iPhone 4 !

Disclaimer: This guide is for testing & educational purposes only. I’m not responsible for any loss of important data or malfunctioning of your iPhone.