The Dev Team just released their unlock for iPhone 4.3.1. This updated version of ultrasn0w brings support for the iPhone 3Gs and the iPhone 4 that are exclusively using these basebands: 01.59.00, 04.26.08, 05.11.07, 05.12.01, 05.13.04, and 06.15.00.

In this post, we’ll guide you into unlocking your iPhone 3GS or iPhone 4 on any of the above basebands, and running the latest iOS 4.3.1…

First, you have to make sure your iPhone comes with any of the baseband versions listed above. If it doesn’t there isn’t much solution for you at this time.

If your iPhone is however running any of those versions, you can easily update to iOS 4.3.1 while preserving your baseband, which will allow you to unlock using ultrasn0w 1.2.1.

Step 1: You will first have to jailbreak and update your iPhone using one of these methods:

Step 2: Once you are updated to iOS 4.3.1, launch Cydia, go to Manage > Sources > Edit > Add,  and type in the following repo: This will install the ultrasn0w unlock on your phone.

Step 3: After installing UltraSn0w, make sure to reboot your iPhone.

At this point, you can insert a different SIM card. If you install T-Mobile, make sure to disable 3G in Settings > General > Network.

Thats all there is to it. The whole jailbreak+unlock process is fairly easy and shouldn’t take more than a few minutes.

Let us know if you have any question.

  • roshan

    my iphone is 4.3.1 and the baseband is 4.10.1…how can i unlock these baseband..pls help me

  • Shakeel

    me too need solution for the same

  • loai

    same Here :/

  • Kim

    don’t dream about unlocking those basebands, they ain’t gonna help you anymore.

  • Stino

    Can iphone with a 4.3.1 and a 05.16.02 baseband be unlocked? This baseband isnt listed on this page.

  • vera

    just jailbreak my 3gs iphone (3.1.3) with 05.12.01 baseband.
    The Cydia shows SHSH: iOS 4.1, 4.3.5
    my question is – do i have to update it to iOS 4.3.1 (as shown on ur direction) ?
    if NOT, should i just jumo on step 2?
    thanx alot!!!

  • sanjeev chahar

    my frien bring a iphone 4 from uk..its already can i unlock it??…can i do a tether boot from any pc or do i need to connect with same pc from which it was jailbroken??

  • Aji Sukardi

    where do you find the baseband of the iPhone?

  • Ibrahim Aloo

    My iphone has no sim card therefore i cant download any software for it, what do i doto unlock it

  • Beny

    I have a 3gs that has been updated to 6.0, I can use my straighttalk sim for calls and text, and sometimes mme. do I have to jailbreak to upload a new APN? What program will I need to jailbreak? Will I have to down grade my IOS? Please Help

  • Momo

    What if the iphone4 is from japan and i used it in the philippines. They said dont update the ios 4.3.1 into ios higher cause you didnt use it anymore.