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.

  • brocclibob

    I updated to 4.3.1 (on a 3gs, 05.11.17) using snowbreeze, and then installed ultrasn0w 1.2.1. All i get is searching. Im guessing that means you can’t use snowbreeze?

    • brocclibob


    • Musaid

      did u restart ur phone? that should fix it hopefully

    • Musaid

      restore it again with the custom ipsw, this time take the sim out.. install ultrasn0w, reboot the device, then insert sim.. i did it again, its working for me now 🙂

  • Diddyo

    This ultrasn0w update won’t cause any problems for those of us remaining on 4.2.1 will it?

    • Neil

      No, it only apply to 4.3.1

  • Morgan

    What about us with other basebands…..??? , We just have to wait how much…?? another 6 MONTHS !!!!!????? , im tired of this bs…. im buying gevey sim….

    • Juan

      you know, the dev team doesn’t owe you anything. go ahead, get the gevey sim unlock. good luck.

  • Robert

    So how did i get, say, baseband 5.14.02? Just bad luck?

    • Neil

      When you updated to 4.1 it came with iOS 4.1

  • DebTym

    Same question with about us who remained 4.2.1 , will updating affect our overall performance??? (or whatever you call it) Though I updated mine already, but still i’m on 4.2.1

  • iceman

    im getting the rebel sim… i cant wait for another 6 or maybe longer for my iphone 4 to get unlock.

  • Annoyed

    Really pissed with this I don’t want to update to 4.3.1 as I’m on 4.2.1 with 05.15.04 why can’t u make it compatible with ALL basebands!

    • Blubber

      Why don’t you learn how to program and Hack on your OEM and Write your own unlock for everybaseband you like?!

      As Long As you are to stupid to make One on your own, don’t Blame Others for doing the Best they can to help People out there..

      • davkay70

        yeah i with ya there LOL damn he a troll

  • dabe

    Stop saying the same thing over and over please. They told us a million times no new basebands will be unlocked, this just makes it compatible with 4.3.1. Many iPhones are unlocked/unlockable just sell yours and buy one, problem solved. the Dev team didn’t sell you your iPhone did they? They don’t owe you shit

  • dabe

    Thanks I’ll be using the Unlock tomorrow!! :))

  • Jansa

    Just unlocked my 3GS on 6.15. Great success. Thank you!

    • Vinstant

      I have iphone 3gs on firmware 4.1 and baseband 05.14. Does the new redsnow or pwnage tool update allow you to go from 4.1 to 4.3.1? Or should I follow the instructions from an old tutorial to update my baseband to 6.15 then update to 4.3.1?

  • suprafitch

    I having problem on T-mobile data network after update from 1.2 to 1.2.1, no more Edge speed and instead GPRS speed is shown after the update.

    • Luqman

      Reset your network settings. After ios 4.3.1 update on 1.59 it happened to me as well when after a jailbreak cellular data network was missing under network. If you are jailbroken make sure you reset network settings only.

      • suprafitch

        Yes I did!! It does detect the T-mobile data network by, but the singal from Edge downgrade to GPRS once updated 1.2.1

        I have no problem showing Edge signal when use 1.2

  • VnABC

    Title of the article is misleading. Just read the title, people thought that they can unlock iOS 4.3.1, but actually with certain old basesbands only!!! It likes a promotion with a fine line *some restriction apply or Buy a BMW for $20K (…with 20 or 40k down payment)… Anyway, this helps for some, but useless the the rest!

  • Moe

    Hi why we disable 3G in Settings on tmobil
    In the time they support 4 g

  • Musaid

    i am wondering the same thing as brocclibob.. i did not update to 4.3.1 yet, just wanted to know that if i update with sn0wbreeze will i be able to use this unlock? i dont have a mac to use pwnage tool

  • Musaid

    *i have a 3gs with new bootroom (MC), 05.12.01 and os 3.1.3 atm

  • renzik

    Quer dizer que não funciona no bb 03.10.01?

  • Johnny

    Is there any way to change your iPhone 4 baseband to any of the mentioned above? I’m stuck on 03.10.01 IIRC.

    • Kickstar13

      Nope, not yet at least.

  • Robert Taylor

    What about 4.10.01?

    • Kickstar13

      The ultrasn0w unlock tool only works for 1.59.00 baseband for the iPhone 4. There is currently no software unlock available for the iPhone 4 on baseband 2.10.04, 3.10.01, or 4.10.01.

  • Musaid

    ok i am a little scared now.. i updated to 4.3.1 through sn0wbreeze, my baseband is still 05.12.01 but when i installed ultrasn0w and restarted the device its showing no sim.. any help PLEASE?

  • Musaid

    hey it was my bad, i left the sim in while jailbreaking and installing ultrasn0w.. restored again without the sim and its working now.. THANK YOU 🙂 i really appreciate the efforts u people make.. and it was explicitly mentioned to insert sim after rebooting device, i didnt follow instructions properly

  • martin

    It doesn’t work for me – I have 4.3.1 with 06.15.00.
    After installing ultrasn0w and rebooting, if I take out my Rogers sim and insert a T-mobile one the iphone says its detected a different sim and tells me to connect to iTunes. Then iTunes says the SIM is unsupported.
    Any suggestions

  • Musaid

    did u disable 3g?

  • Luis

    i still dont find any atractive at all 4.3 :/

  • Martin

    I found out my problem – I repeated the process with the target sim installed from the beginning and then it worked.

  • El

    Q: I’m using 3GS 3.1.3 with 04.26.08 baseband, will ultrasnow work for me?

  • Abhishek

    Any hopes of unlock coming up for iPhone4 iOS 4.2.1 with bb 03.10.01? Any expected timeline?

  • yangsikyi

    when u make 04.10.01 unlock program…..?
    i am waiting u r program T.T

  • JC

    I bought my phone carrier locked- I called the carrier who then unlocked it (said I was going overseas for a holiday when asked why).

    Do I require UltraSn0w to still be installed or can I simply use Redsn0w and all will be well?

  • Eduardo Fettermann de Andrade

    hi there i did all procedures and doesnt worked, my i phone 4 has firmware 4.10.01 the version is 4.3.1(8g4). can i unlock it??

  • timothy

    F.U.C.K all this Bullshit, I’m getting gevey or rebel sim, just because i’m stuck with Apple Damm it! If i can spent $700 than i can afford $70 Sim, can’t wait!

  • Sarge812

    firmware 4.10.01 the version is 4.3.1(8g4) STILL NO UNLOCK!!!!! … wow.. wifee is Pissed.. I spent over 500 on this phone… adn cant use it.. what an expensive IPod…. anyone have any sugestions on unlocking??? oh.. adn BTW… the GEVEY SIM.. what a joke.. I bought that… and it dont work… It sees the TMobile SIM for about a Minute.. then comes back with “INVALID SIM” …. wow…

  • rocker

    i’ve 3gs with ios 4.3.1 and 5.16.02 firmware..
    when will the unlock be available,
    plz tel me???

  • my iphone installed baseband 04.10.01 using 4.3.2. firmware, i have iphone 4g is there any metho jo unlock this baseband..
    your support is always appriciated.

  • Robert

    Really confused. I have:

    Iphone 3GS
    Version 4.0 (8A293)
    Baseband 5.13.04
    Windows (No Mac)

    Looking at the above instructions, it tells me to first: “update to 4.3.1 while preserving 01.59.00 baseband using TinyUmbrella”. When I click on the link, however, it is only for Iphone 4.

    So my question is – can I actually unlock this phone? I have looked at all the links and it appears to me that I can only do it if I have a Mac computer running Pwnage Tool. But this article makes it seem like you can unlock 3GS given my setup.

    • Robert

      So actually i figurrd it out. Used and then unlocjed to version 4.0. Im not going to even attempt going to 4.1 or beyond since i dont have a Mac

  • DJ_iPhone4

    I have iPhone 4 bb 2.10.
    Can I upgrade it to bb 6.15 with iPad’s bb?

    Can I unlock it by doing that?

  • jon

    I have a iphone 3gs firmare 3.1.3 with a baseband of 5.11.07 and i need help with preserving the the baseband so i can unlock it agian. Can anyone help me. thanks

  • Koliqi

    where is unlock for 02.10.04 nobody can unlockd

  • mobi

    is there any ETA releasing of unlock iphone 4g 4.3.2 firmware with baseband 04.10.01.
    i wana go to my home land and need to unlock my iphone.
    please help me..

  • Obi

    This might sound like a stupid question.

    I have a 3GS 4.2.1 with firmware 05.15.04
    Last few unlocks didn’t include this baseband/firmware. My question is , if I upgrade to 4.3.1, will my firmware also get upgraded to another version which can be unlocked?


  • OP

    I have iPhone 3GS, with firmware 4.2.3 and I do not have original SIM and its stuck on itunes, I cant get any further..
    How do I unlock? I’m so confused.. I dont even know BB, how can find BB??

  • Gabbe


    Does anyone know when there is an unlock for bb 05:16:02

    // Gabbe

  • Madhu

    I have a 3GS 4.3.1 with firmware 05.16.02
    Is it possible to unlock this phone? I noticed in the thread that this firmware was missing. Is it possible to have a diff firmware which could be unlocked?
    Kindly help.

  • Madhu

    I also read in a forum that I can upgrade the 5.16.02 firmware to 6.15.00 and then unlock. Am I missing something?

  • Tenzing

    I phone 4 4.3.1 with baseband 4.10.01. . Need to unlock . If anyone has a solution please help .?

    • Dipanjan

      I have successfully unlocked my iPhone4 4.2.1 bb 2.10 using Gevey sim emulator. It will also work on 4.3.3.

  • barro

    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.

    My Iphone updated to 4.3.1 .. and I did all steps but it didn’t work ..
    sim still locked .. what should I do .?? any other solution ?

    Plz Help

    • Dipanjan

      Ultrasn0w won’t work on BB > 1.59.00.
      Try Gevey sim, I was successful in unlocking my iPhone 4.2.1 BB 2.10 with this.

  • barro

    Dipanja Thanks for your replay ..

    but I’m from Saudi Arabia .. How can I get gevey sim .. online yeah ?

    .. But How can I use it and what should I do how does it work ?

    Thanks again

  • Mayil

    Hi Dipanja, I have an Iphone4 4.3.1 version and the firmware is 03.10.01. I think there is no option to unlock the mobile as of now. I just want to know whether Gevey sim is advisable for Iphone? As far as i heard thru some of my friends, they were telling that the Gevey sim is not safe and it might spoil the mobile and its not legal also. If you can give me the background & function of Gevey sim, it would be great. So that i can also use it. Am from India

    • Dipanjan

      I am on iPhone 4.2.1 bb 2.10. I used Gevey sim ordered thru, using it now and so far my iPhone not giving any trouble.
      Also I was able to enable Cellular data network using iPhone Configuration Utility (available in Apple Downloads).

  • Mayil

    Thanx Dipanjan, how much did u pay for the Gevey sim.. In Bangalore there are lot of rates from 1700 to 3500 people are asking.. If you are from India, can u give me your no, want to discuss with you abt this

    • Dipanjan

      Yes, I am in India. As I mentioned earlier, I ordered the gevey sim from site. I got a offer of Rs. 845. You may get it for Rs. 990-1000 max (Buy Now option; not the bid). I got it in proper condition and it was brand new.

  • nothing clear to me

  • stacy