Technically, it’s not possible to unlock an iPhone that has been updated to iOS 4.1 because there is no unlock available for the iOS 4.1 baseband. Now depending on your situation, there might be a way to unlock your iPhone.

If you are still on iOS 4.0.1 (or even earlier version. ie 3.1.3), then you can use PwnageTool to jailbreak your iPhone while preserving the baseband (see our guide here). This will make sure you update to the latest iOS version but don’t update the baseband, which is the key part in unlocking your iPhone…

Again, if you have already updated to iOS 4.1 and upgraded your baseband, you will not be able to unlock. There probably won’t be any unlock for iOS 4.1 and you’ll most likely have to wait for iOS 4.2.

This being said, here is what you have to do to unlock your iPhone 4.1 using UltraSn0w. This will work for the iPhone 4, iPhone 3GS, and iPhone 3G.

Step 1: Make sure you’re still on iOS 4 or iOS 4.0.1.

Step 2: Jailbreak your iPhone using PwnageTool.

Step 3: Go to Cydia and search for UltraSn0w. Download and install UltraSn0w.

Step 4: Reboot your iPhone. Done!

You should now have an iPhone unlocked with UltraSn0w.

  • Ady

    Sab pls help

  • Ed

    So question guys and girls,

    I tried to downgrade my iphone 3g from 4.0 to 3.1.3. Is it possible that it could have upgraded my firmware without me wanting it to? The reason why I asked is because at a point in the downgrade a pop up should have come up saying “error” and thats when I was suppose to use Umbrella or Recbox to “get out of recovery mode”. Well that pop up never happened and it completely restored. After this I was stuck in recovery mode and couldn’t get out till I found a way. But when I found a way I upgraded back to 4.0 and finally was able to jailbreak it again, but now I am not able to unlock? My iphones firmware says its 05.13.04 so there shouldn’t be a problem with me unlocking. Ultrasn0w is installed in Cydia but I have no carrier? What should I try????????

  • TheChosenOne

    Guys I accidentally update to 4.1 on my iPhone 3g, I am on a Windows computer. PLEASE HELP!!!!

  • Ed

    Sorry buddy, your stuck until the unlock comes out next month.

    DevTeam should be releasing the new RedSn0w Unlock for 4.1 a couple days after the new Apple 4.2 firmware comes out sometime next month.

    The reason why we have to wait is because they want to make sure that Apple doesn’t come out with a fix for the PC unlock with the 4.2 package.

    It really sucks, but you have to wait until it comes out. I think I am also stuck in that situation, but not for sure because I didn’t upgrade, I downgraded and now I am stuck.

  • W


  • sjpapa

    Well if I read the ‘downgrade’ section correctly, if one ‘accidentally’ upgraded to 4.1 or got a 4.1 iPhone, the full downgrade described in that very section will restore both the baseband and the iOS. Correct?

    Then after the downgrade one may proceed to the upgrade to 4.0.1, jailbreak and then upgrade to 4.1 while preserving baseband modem configuration for unlocking. Correct? Or did I miss anything?

    Many thanks

    • whatchasay

      baseband cannot be downgraded… if you have upgraded to iOS 4.1 using iTunes restore you would have upgraded your baseband to 5.14.02. There is no unlock for this baseband.

  • Jose

    Questiion i have an iphone 3gs 4.0.1 and a modem firmware 05.14.02 can this be unlock or do i have to wait for the new up date to unlocke it???? thanks

    • whatchasay

      you have to wait for unlock. Ultrasn0w cannot unlock 05.14.02 BB


    HI Sebastien,

    Thank you very much,

  • Jose

    Thanks for your answear whatchasay, have to wait ok…..

  • sjpapa

    This is really strange. This means that the modem firmware is something like a “BIOS” and cannot be overwritten by subsequent downgrades or restores. This means that if I accidentally hit the Upgrade button on iTunes, my unlocked 3GS 4.0.1 gets pooped. Hence no more calls as no ATT here around. I had the impression that the restore overwrites everything to the flash, but apparently its not the case. The modem firmware stays to the last version…

  • flafora

    I have a 3G phone with iOS 3.1.2 and baseband 04.26.08. It was jailbroken and unlocked with PwnageTool and Ultrasnow. I understand that if I follow the instructions given here, the baseband will not change after the jailbreak and the unlock.

    However, if I do a “normal” upgrade to 4.01 via iTunes the baseband will upgrade to 05.13.04 but the iPhone will not be jailbroken nor unlocked anymore. However, after the upgrade to 4.0.1 I can update to 4.1 and unlock it.

    So the difference is that in the first case I end up with baseband 04.26.08 and in the second case with 05.13.04. My question is: is it worthwhile to go through the 4.0.1 upgrade just to have baseband 05.13.04 instead of 04.26.08? In other words, what is the advantage of having 05.13.04 instead of 04.26.08?


  • if you have Iphone 3G model only!!!!
    and have upgraded to 4.1 jailbroken with CW

    To unlock there is a tool out that can patch the bootloader โ€“ I thinkits called Fuzzyband and you can download via Cydia. so if you stuck on baseband 05.14.02 this will patch this , so the baseband can be changed to a earlier version and therefore then be unlocked.
    this then can be followed up via ultrasn0w to unlock phone to any network provider..

  • Angel

    I have a question… i dun know where to post this question!

    I have a 3GS with the 3.1.3 i had it jailbroken with blackrain so whenver i turn it off it goes back to “connect to itune” when i tried to restore it with 3.1.3 by doing “shift + restore” it won’t let me store..

    how can i do anything.. to jailbreak it with “” ๐Ÿ™ any idea? Help please…

    I should have updated to 4.0.1 and did teh jailbreak ๐Ÿ™

    Help me please… thanks

  • unlimitedream

    i upgrade iphone3g to 4.1 n it’s not working again i downgrade to 4.0 but coz of baseband is 05.14.02 now it’s not working.Please help.I tryed 3g fuzzyband downgraderhow. From cydia but still it is not downgrade . And now i can’t use my i phone. stuck with my nokia. Please help me. I don’t have mac. Only window. Please

  • P

    I need 4.1 unlocking any1 help me…. Help

  • iphone4.1

    I bought a new iphone 4 with os 4.1 and baseband 02.10.04.. I was able to jailbreak and not able to unlock. Is there a way to unlock with phone

  • XDark

    so Sebs, i see lots of software being sold to unlock the iphone4.1 …. any input on that?

  • voodoo

    guys plz there is no unlock for BB 05.14.02 u have to wait for IOS 4.2 to come out in NOV sherif have found a BB crash that will lead for a unlock musclenerd also confirmed that it will be a unlock for BB 05.14.02 after IOS 4.2 is out he also said on tweeter that it may take a day or two after the new FW to have the new unlock out to test few things ,if the unlock is out now apple will patch it in IOS 4.2 so ppl be patient till NOV when IOS 4.2 is out u will have a unlock for your 3G AND 3GS with BB 5.14 for iphone4 with BB 2.10 there is no unlock yet as hackers found a crash for that BB but still doing some tests on it so for the moment only 5.14 have been confirmed to have a unlock coming next month.

    so u guys know this iphone4 don’t have the same BB chip as 3G and 3GS

  • People come here for step by step instructions. Usually, the instructions are good. In this case, the post is vague and confusing. None of us has a spare iPhone to risk bricking while trying to figure out what Sebastien is trying to say here.

    So please, replace this article with clear, reliable, step by step instructions.

  • reddy

    i am using an iphone and i have updated it to 4.1,,,,can i unlock it!!!!as i heard unlock is not available for baseband

  • voodoo

    no u can’t wait for it after IOS 4.2 is out

  • subrat

    Dear Seb,
    I have 4.1 OS in my iphone 3G with 5.14.02 baseband. I did a jailbreak on it today using the Pwnage tool. Everything went well and now I have cyndia on my phone. But the problem is, it does not detect any service now (I was on at and t). Now that the IOS 4.2 is out. Will I be able to unlock this phone sometime latter in Nov using ultrasnow. I really want to use my phone again to stay connected. Please help…

  • RiKo

    Accidently I upgraded my Iphone 4 4.0.2 to 4.1 and baseband was 02.10.04.. I know I need to wait new Ultrasnow. But some guys say that u will not be able make Unlock, you losed unlock, may be forever. Is it true?

  • Bill

    hey, 4.2 is coming out. .so is unlock for 4.1 5.14.02 and 2.10. right??? any answer.. plzz.. DEV team.. help us.. thx.. ๐Ÿ˜‰

  • voodoo

    ppl understand this 3G and 3GS have BB 5.14.02 the unlock will be out after IOS 4.2 is out
    Iphone 4 with BB 2.10 still on the making .
    @ subrat yes after IOS 4.2 u can unlock for 3G it’s been confirmed.
    @ RiKo no it’s not true a crash have been found but hackers still wsorking on it so u need to wait a bit long for unlock.
    @ bill 5.14.02 yes that’s right , 2.10 not yet still on the making.

    in twitter MuscleNerd from iphone dev said :
    -yes, despite all the recent (and ridiculous) twitter drama, there is a very nice unlock coming soon. If I don’t get killed.
    -if you’re on 3G or 3GS, just a day or 2 at most after 4.2 is public (just enough time to verify stuff).
    -we have an unlock for that, but gotta wait til next cat&mouse from Apple (official 4.2).
    -it is 100% that a new baseband unlocker will be out for 3G+3GS. Still working on the i4 side of that though.

    thats MuscleNerd responding to ppl asking about unlock.
    i hope this will make things clear for ppl .

  • obeyme

    so when exactly will 4.2 come out?

    • RiKo

      till 12 November it will release

  • kimo

    Hi All
    any news yet in relation to the release of V-4.2 by Apple?

  • neo

    i bought an i phone 4. ios 4.1. baseband 02.10.04… is there a way to unlock my phone ??
    i was able to jailbreak it though.

    pls help.

  • VSK

    i have updated my iphone to 4.1,,,i guess the baseband is updated….is there any thing i could do to unlock it…plz help

  • DeLaGi

    So someone said v.4.2 would be out by now, but its not. So does anyone the actual date?

  • ampy

    cydia crashes after jailbreak, cant access to unlock to Ultrasnow – any help

    • ampy

      just got in after a couple of reboots…

  • Ak

    I there an unlock for iPhone 4 4.0.2

  • Rjb

    I guess I’m asking the same unanswered question…

    I have an iPhone 4 running 4.1 and baseband 02.10.04, it was purchased in the USA and came pre-loaded with the aforementioned firmware.

    I would like to use it here in the UK. Can I unlock the phone from AT&T?

  • Rjb

    BTW, this article is still misleading. Shouldn’t it say…

    “This being said, here is what you have to do to unlock your iPhone 4.0 or 4.0.1…before upgrading to 4.1…”

  • Cryptic

    Now that iOS 4.2 is out, can someone pls update when will the unlock for iphone 3G iOS 4.1 be released? desperately wiating for it. ๐Ÿ™

  • Cryptic

    Seb, plsss give some updates on unlock for 4.1 baseband 5.14.02

  • Rjb

    Same here seb, 4.2 is out now and I have new iPhone 4 running 4.1 and baseband 02.10.04. Please can we have updates….

  • Rondell

    I think i read that there won’t be an unlock for 4.1. cuz 4.2 is out. So I think they are just going to focus on unlocking 4.2. KEYWORDS I THINK

  • oh bhen k lodeo mai takran maar maar k thak gaya koi tariqa dasdo free unlock krn da

  • Elisabeth

    But if there is un unlock for iPhone 4 4.2 and I have 4.1 with baseband 2.10 will I be able to upgrade to the newest baseband and after jailbreak and unlock?

  • Payal Negi

    I just got an Iphone 4 from US with version 4.1 and baseband 02.10.04, for use in India , I have asked many unlockers but nobody is able to do the unlock, kindly provide some solution what should I do??

    Should I wait or should I sell off the iPhone 4??

    • Rjb

      I’m in exactly the same position. My wife bought me an iPhone 4 to use in the UK. It’s on version 4.1 with baseband 02.10.04. I am seriously considering trying to sell it now as I’ve had it over a month waiting for an unlock solution. There are even websites who charge for a solution claiming to be able to do it, but I just emded up out of pocket even more!

      If I find a solution I’ll post it on twitter. Let me know if you get an answer as nobody seems to know anything about i4

    • Rjb


      i4 from the USA locked to AT&T with 02.10.04.

  • payal negi

    surely i will reply if i will get something possitive.

    • Rjb

      Same here…

  • bgra

    afff que demora ๐Ÿ™

  • Rafael

    hi Sebastien
    thank you for this blog. i just did the jailbreak&unlock for my 3G.
    appreciated the information and the links for downloads.
    greetings Rafael

  • livein_real20

    I have done as it was said for iphone 3gs 4.2.1 unlocked it but no sim is working of mine in India only what i brought it from UK (O2) Any idea or suggestion pla

  • Vanessa

    HELP!!!!!!!!!!! I need to unlock an Iphone 3G Version 4.1 and the firmware is 05.14.02 Locked with Fido!! Please Helpppppppppp!!!!!!!!!! I’ve asked a few ppl and they all tell me they can’t unlock it!!

  • adeniran adetayo

    Hi Sebastien,
    I received a iphone 4 4.1 (8B117) baseband 02.10.04 as a gift from my friend in the US since november. how do i unlock it? Please provide a step by step procedure. I will appreciate your assistance.

  • trigger

    Hi, I jailbroke iphone 4 (4.1/2.10.04). using limerain. I then ran Ultrasn0w, which installed successfully but failed to unlock. Did I permanently destroy the ability to unlock?


  • Jacob

    So i need to use PwnageTool to create a restore with 4.1 version and do the restore
    and then i willbe able to unlock right? =) thx

  • Jason

    I have an iphone 3G (I don’t know how to figure out my BB), and I have successfully jailbroken and unlocked it. However, when I put in my foreign SIM, it doesn’t work still. It can’t find the carrier….what could be causing this?