Unlock iPhone 4 & iPhone 3GS on iOS 4.3.1 using Ultrasn0w 1.2.1

Apr 10, 2011 - 3 Comments

A new version of the Ultrasn0w iPhone carrier unlock utility has been released with iOS 4.3.1 support.

Note ultrasn0w 1.2.1 is not a new unlock and it will not unlock new baseband, but it does allow you to maintain your carrier unlock while upgrading to jailbroken iOS 4.3.1 using PwnageTool or Sn0wbreeze to preserve baseband.

UltraSn0w 1.2.1 will unlock iPhone 3GS or iPhone 4 on baseband 01.59.00, 04.26.08, 05.11.07, 05.12.01, 05.13.04, and 06.15.00, you can check your iPhone baseband from Settings > General > About. Any baseband outside of these versions is not currently unlockable.

Download & Install Ultrasn0w Unlock for iOS 4.3.1

Mac users will need to download PwnageTool 4.3.1, iOS 4.3.1 firmware, and jailbreak the iPhone iOS 4.3.1 using PwnageTool to preserve their existing baseband. Windows users can do this with Sn0wbreeze.

After you have upgraded to iOS 4.3.1 with preserved baseband, here’s how to download and install ultrasn0w 1.2.1:

  • Launch Cydia
  • Tap on “Manage”
  • Tap on “Sources”
  • Tap “Edit”
  • Select “Add”
  • Enter the following repository: http://repo666.ultrasn0w.com
  • Tap on “Add Source”
  • Cydia will add the source repo, now search for “ultrasn0w 1.2.1” and download and install the unlock
  • After ultrasn0w 1.2.1 has been installed, restart your iPhone

Your iPhone 4 or iPhone 3GS with preserved baseband will now be unlocked with iOS 4.3.1.


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Posted by: Manish Patel in iPhone


» Comments RSS Feed

  1. Sajid says:

    I have an Iphone 4 with ios 4.3.1 which is carrier locked and i am using Gevey to unlock it, is there a permanent carrier unlock for my device ? Please help.
    Baseband is 04.10.01-ICE_2_13

  2. […] patched by Apple and the unlock community finding new methods around the carrier locks. Recently iOS 4.3.1 was unlocked with ultrasn0w 1.2.1 but it requires a user to jailbreak an iPhone with iOS 4.3.1 while preserving old baseband that […]

  3. […] If you’ve been holding out on updating to iOS 4.3.1 in order to jailbreak without a tether, now is your chance. If you rely on the ultrasn0w unlock, be sure to preserve your unlocked baseband and then use ultrasn0w unlock for iPhone 4 & 3GS with iOS 4.3.1. […]

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