How to Unlock Your iPhone 4.2.1 with UltraSn0w

By , Nov 29, 2010

The Dev Team has updated their UltraSn0w iPhone unlock for iOS 4.2.1. UltraSn0w 1.2 will unlock iPhone 4 baseband 01.59.00 and iPhone 3G/3GS basebands 04.26.08, 05.11.07, 05.12.01, 05.13.04 and now 06.15.00.

If your iPhone 4 is not on baseband 01.59.00, you will not be able to unlock it. If your iPhone 3G or 3GS is on one of the baseband version mentioned above, then you can follow the instructions below…

If your iPhone 3G or 3GS is not on one of the baseband version mentioned above, you will have to first update your baseband to 06.15.00. See our PwnageTool tutorial or RedSn0w guide to do this.

This process doesn’t come without its share of risks, so it is very important you read this before doing anything. Seriously, make sure you read it.

Step 1: Make sure your iPhone is jailbroken using PwnageTool or RedSn0w.

Step 2: Launch Cydia, and search for UltraSn0w.

Step 3: Download UltraSn0w.

Step 4: Reboot your iPhone.

Your iPhone is now unlocked. There is no real way to test it until you pop a different SIM card in.

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  • Nash

    I have a 3GS running 4.2.1 with 5.15.04 baseband.

    I have jailbroken it with Greenpois0n RC5

    I need to unlock it, even if it means upgrading the baseband to 6.15. I dont mind losing the GPS.

    Can someone pls guide me how to unlock? the tutorial here is confusing.
    ( http://www.iphonedownloadblog.com/2010/11/29/unlock-iphone-4-2-1-ultrasn0w/ ) says you need to use pawnagetool to upgrade to 6.15 baseband.

    But that page (http://www.iphonedownloadblog.com/2010/11/28/how-to-prepare-your-iphone-for-unlock-with-pwnagetool/) says you need to download ios 4.1 for your 3GS.

    If you try to use Redsn0w (http://www.iphonedownloadblog.com/2010/11/29/how-to-prepare-your-iphone-4-2-1-for-unlock/) it asks you to use a tethered jailbreak

    Can someone solve this puzzle please?

    Thanks!

    • mad

      no

  • Beleza

    Hi I have a question,

    My brother had his IPhone 3G unlocked a few years back but a lot of recent apps weren’t working on it so he wanted to update his software and see what would happen. He updated it through itunes and I then helped him through the process using Pwnage Tool then UltraSn0w and everything seemed ok but then his phone wouldn’t find the network. Went to check and the baseband turned out to be 05.15 so we restarted the process to install 06.15. Everything worked out and his phone is back to being unlocked but he has no apps and all his contacts are gone. Will restore from a previous back up reinstall the apple software and we’ll have to repeat the process or would it be ok so he can get his contacts back? If he shouldn’t do that is there anything you’d recommend? Thanks for all the help!

  • parth

    hey after d jailbreck my iphone 3g i have problem that my phone cant get network nd also not show carrier in satting opption

  • http://www.facebook.com/louchy.alouchy Ali A Ayoub

    hi can anyone help me ?
    i have iphone 3g with version 4.2.1 ,,, modem firmware 06.15.00 how can downgrade the modem firmware to 05.14.02 ? plz help me thank u

  • BHATI ANIRUDDH

    Masters Thanks u…for unlocking…. 3g bb 06.15.00 version 4.2.1
    but Please help i have one problem..
    i can not internet tethering with my pc (win 7)
    what i do…??/
    when install my bsnl sim tethering option is not there..
    but when i install airtel sim it show tethering option…
    please help…….

  • http://www.facebook.com/people/Christopher-Brooks/602182410 Christopher Brooks

    Hi guys sorry for the intrudesion my Iphone 4 version 4.2.1 BB 03.10.01was jailbroken with greensn0w but not unlock. The phone was sent to a mobile store to be unlock but the pearson who was trying to unlock did’nt know what the hell they were doing and now my cydia is mess up and won’t load any packages without an error, so I had to deleted Cydia. Whats the safest way for me to install Cydia and to upgrade BB to unlock.

    Any solution would be greatly appreciated……Thank You Chris

  • http://www.facebook.com/people/Christopher-Brooks/602182410 Christopher Brooks

    Hi guys sorry for the intrudesion my Iphone 4 version 4.2.1 BB 03.10.01was jailbroken with greensn0w but not unlock. The phone was sent to a mobile store to be unlock but the pearson who was trying to unlock did’nt know what the hell they were doing and now my cydia is mess up and won’t load any packages without an error, so I had to deleted Cydia. Whats the safest way for me to install Cydia and to upgrade BB to unlock.

    Any solution would be greatly appreciated……Thank You Chris

  • http://www.facebook.com/profile.php?id=1260502576 Myron Meadows

    i have a iphone 3g with a 4.2.1 and 6.15 i have jailbreak it with redsnow and unlock it with ultrasnow but when i put my sim card in the phone freezes and keep rebooting but when i take it out it works fine can someone help me plz

  • http://www.facebook.com/profile.php?id=712657541 Rik Scott

    The whole reason I want to unlock my phone is because its locked to AT&T which isn’t available in this country. Since I can’t use a 3rd party carrier, I can’t download via Cydia, therefore I can’t unlock the phone. Catch 22.

  • Naeem Raza

    i have iphone 3G with 3.1 firmware kailbreak wjat tools should i need for upgrading my firmware to 4.2.1 …
    first i update my firmware to 4.2 and then Jailbreak it again !!! is it right and also after completing upgrade my phone have contacts and Message in inbox or not. so i take cackup plz tell me how to take backup and then after upgrading i put all those Contacts numbers and messages to my upgraded phone…

  • http://www.facebook.com/SRehan.7 Syed Rehan

    I hav a IPhone 3G and I want to install ios 4.2.1 but i want to know that can I unlock my IPhone if I jailbroke it using Greenpois0n

  • vn

    what i need to do if my iphone need unlock because i cant acces to it now too ?

  • Gentrit

    I jailbreaked my iPhone 3G ios 4.2.1 and when I lounch CYDIA I do install the ultrasn0w but the version of ultrasn0w is 1.2.5 … it doesn’t work with my iOS … Can anyone help me fix this ?

  • nofreak

    that was detailed tutorial I was looking for. I had an old iphone 3g which sim card slot broken which few famous repair shops said they cant jailbreak and unlock after trying for two days.. I followed ur instructions and it was plain smooth to unlock and jailbreak..

  • Shemsudin Ismael

    i have iphone 4 ios 4.2.1 it’s BB is 03.10.01 if there is any way to unlock the BB plz help

  • mack21boom

    Just jailbroke my iphone 3g with redsn0w… tried to download ultrasn0w but it says cannot comply “Depends iOS Firmware .=3.0″ my ios is 4.2.1 and baseband 6.15.00. any ideas?? any advice is much appreciated thanks!!

  • itzikma

    IT WORKS !!!!!!!!!! 10X