iPhone 3G SIM unlock guide – yellowsn0w unlocks iPhone 3G for any GSM network

Welcome to IntoMobile’s iPhone 3G unlock tutorial. In this step-by-step DIY guide, we’ll walk you through the steps needed to unlock your iPhone 3G’s GSM baseband (cellular modem) for use on any GSM network in the world.

The software-unlock solution, curiously dubbed “yellowsn0w” by the iPhone-hacking gurus on the iPhone Dev Team, is fairly straight-forward and low-risk. But, be warned, whenever you fiddle around with anything that involves the “baseband,” you’re running the real risk of turning your precious handset into little more than a paperweight – the iPhone 3G is no exception.

The yellowsn0w utility requires that you update your iPhone 3G’s baseband firmware to the newer 02.28.00 firmware version that comes bundled with the iPhone 2.2 OS. The iPhone Dev Team had previously warned against updating the baseband firmware (modem firmware), in hopes of preserving the older firmware. But, thanks to breakthroughs made by the iPhone Dev Team, yellowsn0w works with the new 02.28.00 baseband firmware. In fact, yellowsn0w will only work with the new iPhone 3G modem firmware version – so you may have to update your iPhone 3G to iPhone 2.2 OS (or do a “Restore”) using iTunes. – [Update] yellowsn0w will ONLY work with the 02.28.00 baseband, regardless of which iPhone OS you are running. Update to iPhone 2.2.1 OS through PwnageTool or you will lose any chance of using yellowsn0w. yellowsn0w has been updated to v0.9.7

For clarification:
The yellowsn0w utility isn’t an “application” per se. It is a command string that executes itself upon reboot, and it’s completely invisible to the user. You’ll never see a yellowsn0w icon or any GUI, but you’ll know it’s there when you pop in your pre-paid international SIM card and your iPhone 3G locks on to a tower.

So, with the formalities out of the way, we present to you the iPhone 3G software unlock tutorial:

  1. Ensure that your iPhone 3G is fully (or at least 80%) charged.
  2. Update your iPhone 3G to the iPhone 2.2 OS through iTunes (no Shift-Click or Option-Click required).
    • Do NOT update to iPhone 2.2 OS through PwnageTool or any other jailbreak utility.
    • If you are already running a jailbroken version of iPhone 2.2 OS, you can simply “Restore” your iPhone 3G through iTunes (no Shift-Click or Option-Click required).
    • If you are sure you already have the 02.28.00 baseband firmware installed, skip to Step 3.
    • You an check to see what modem firmware (baseband) version your iPhone 3G is running by navigating your iPhone to Settings>General>About>Modem Firmware
  3. Jailbreak your iPhone 3G using Pwnage Tool 2.2.1. (Find the tutorial here)
  4. Once your jailbroken iPhone 3G reboots, you’ll want to fire up either Cydia or Installer (both of which were automatically installed by PwnageTool (see Step 3).
    • Add “http://apt9.yellowsn0w.com/” to your Cydia “Sources” list (repository list)
    • Add “http://i.yellowsn0w.com/” to your Installer “Sources” list (repository list)
  5. Search for “yellowsn0w” in either Cydia or Installer.
  6. Install “yellowsn0w”
  7. Return to homescreen by pressing “Home” button
  8. Reboot iPhone 3G
    • Hold down “Power” button, then “Slide to Power Off”
  9. You should now have a fully unlocked iPhone 3G!
  • Dadiroow

    i have a 3g 2.2 i jailbreaked with 2.2.1 via the the tutorial and whei got into the cydia and installer it’s telling me (did not find repository), what else can i do? please help.
    thank you.

  • Will Park

    Did you add the “http://apt9.yellowsn0w.com/” link to your Cydia repository list?

  • musico

    I would like to know if there’s a way to restore the phone back to the original unJailbroken, and locked version… is it possible? My major concern here is the warranty issues…

  • Mattias

    I can’t connect to my WiFi or regular phoneservice after i did the Pwnage Tool thing and can’t therefore download yellowsn0w so how do i go from here?

  • samu

    do we have to unlock with sim card or without
    thank you

  • gglaze

    Hi, I’ve done some of reading the last couple of days. I have the 2.2(5G77) version with a 02.28.00 modem fireware. My computers are all windows xp. I want to find the right downloads and tutorials. I’d also like to know the “pos” and “negs” of all this. for ie. one web site said that the GPS would no longer work. I’ve only owned my iphone a couple days. Thanks!!

  • acito

    Guys i have 2 iphone 3g 16gb one at&t and other o2uk i use installer to install yellowsn0w it works great on both of them even whene i change the sim it works without reboot the phone calls in out and sms also..i did try from cydia and i got issues so i recommend to all to use installer!

    Thanx to the Dev team great work!!!!!

  • wendy metcalfe

    Downloaded yellowsnow and it worked perfectly for a week. Now my phone icon will not work, although can still receive calls and make calls with contacts icon, does anyone know how to fix this?

  • jay patel

    i update my iphone 2.2.1 and with update moder firmware. so how to i use any sim or how to unlock my iphon. i allrady done jailbroken
    plaese help me

  • harry

    where can i downlaod iPhone1,2_2.2.1_5H11_Custom_Restore.ipsw
    anyone send me links email ?

  • Adam

    I have tried this 3 times on my 3G iPhone – but it won’t work for Telstra in Australia.
    I have used this 3g phone with the old software & that was fine..I have also used the software on 2g iphone & that works..but this doesn’t.

    How do I know that the yellowsn0w is working after installed?

    When I put in my sim it says “sim locked” – when I unlock it looks normal but then doesn’t go to “searching” (that only lasts 0.5 seconds then “Telstra”. It looks like it unlocks but there is no carrier signal… any ideas?

  • Joe

    im about to buy an iphone but i want to cancel my contract with AT&T to stay with the iphon and use it with my actual provider please tell me the risks about unlocking and jail breking the phone pros and cons

  • Cielo

    If i use PwnageTool in order to jailbreak my phone and i do not have the new firmware version, will i be able to use yellosn0w??

  • N

    When I try to add yellsn0w I get the “did not find repository’ message on cydia so it wont unlock. What can I do?

  • hasham

    i have any iphone 3g firm ware 2.2.1
    i have jailbreaked it but i want to unlock the phone
    there are golden sims to make it work but i want to unlock it is there any way i can unlock it
    for pakistan network

  • William

    Hey, I’ve had my iphone 3g (version 2.2, firmware 02.28.00) since christmas and still haven’t got it unlocked…so annoying! i jailbroke my phone using quickpwn and installed yellowsn0w 0.9.6 through cydia but unfortunately this did not unlock my phone for some reason (even after trying to reboot, toogleairplane mode on and off etc)…so i then i decided to maybe re-install yellowsn0w and try again. ive now installed yellowsn0w 0.9.8 but iphone is still not picking up coverage (still displaying no service!) this is annoying me so much and i really want to get my iphone up and running…any ideas of what i could do to fix this? any help would be greatful.

  • reddevilclock

    hey! it is suck that i don’t aware in updating v2.2,firmware 02.28.00 to the new v2.2.1,firmware 02.30.03 is a disaster to me that i will not able to use my iphone 3g 16gb.it also jailbroke using quickpwn.the v2.2.1 is back to v2.2 but the modem firmware is still the same.i need help.i want to know and how if modem firmware 02.30.03 can degrade again to 02.28.00.tnx.

  • Eric

    Hello ,
    I jailbreak my Iphone 3G with pwnage 2.2.5 tools , everything was going good however the custome restore that have been made save the modem firmware to version 1.45.00 without any option to upgrade it to the version 02.28.00
    How i can upgrade the version in order to have my phone unlocked with yellowsn0w 0.9.8 via Cydia , my card sim so no service !
    any help will be very appreciate

  • VMRO

    I unlock the phone and I can use any GSM on my phone but I can’t connect to the internet using the internet by the new GSM provider. How can I set up the phone to connect to the internet with the new GSM provider?
    Please somebody help me. Thanks

  • lgr

    My Phones is on and working!!
    Only do’ts work the phone with any sim card. Can any editor help please!

  • kmi

    I have 3G 2.2.1 (5h11) modem 2.30 . It has been jailbreak through QuickPwn. Everything done. apt9.yellowsn0w added. yellowsn0w install. But when I put sim it says no service. Any help from anybody. You can email me. Thanks

    • Will Park

      Have you disabled PIN access on your SIM? If your SIM is PIN locked, yellowsn0w tends to throw a fit. If you have a PIN on your SIM, try this: insert SIM and wait for PIN. Enter PIN number. Reboot iPhone by holding down power button and home button together until the iPhone reboots.

      If that doesn’t work, you might want to ensure you have the latest version of yellowsn0w

  • Torton

    Yo W. Park you are a genius. Panamas cable and wireless carrier has ALL its sims locked and you cant disable the PIN. Since release of yellowsnow the only carrier I coudnt get to work was C&W. This solutions you gave of rebooting with power and home button worked flawlessly, i never thought it could work. THanks a millions. You should post this solutions in devs blog since I never saw this solution there. GJ!!!!

  • Ken

    Marvellous, thanks! I was getting worried i made a bad deal when i bought my unlocked 3G.

  • albert

    i jail broke my iphone n it was working for a couple days den it froze.. so i restart it n it only shows da pineapple.. so i reboot it n jailbroke it again n now i dont have any network..help…

  • Louis

    Worked like a champ, thanks! LMHORTA

  • drgsrao

    Dear William Park
    I have iphone 3g 8gb with version 2.2.1 & firmware 02.30.03. I want to unlock this phone for local network in India.it is locked to AT&T ,USA.
    1.How to doit?
    2.Afterunlocking whether the phone works ok as original and can I update to latest firmware ?
    3.inorder to do it do I have to know the bootloader’s version?then how?
    please help me & guide me in this matter
    thanking you for your service for everybody

  • drgsrao

    I have I phone 3g 8gb,2.2.1,02.30.03 firmware.I have windows Xp on my computer.Can i unlock this without jailbreaking .Please let me know How to do this
    thanking you

  • vanvu vo

    how about unlock iphone3G,it can use Three sim (3 network).

  • brett parsons

    Hey There, So i did the jail break deal with my phone using the pwnage tool, then did everything thing it said to do in order to unlock the iphone and that seemed to work ok too. BUT!!!! I rebooted my phone, and i have no service and the phone doesnt seem to have reconized my sim card. any ideas?


  • Jeff

    Do you unlock the phone with or without the sim card?
    What should I do for my firmware it’s 04.26.08 do I try to restore?
    What kinds of negatives things can happen to my iphone and computer by downloading Pwnage and yellowsn0w?
    Is T-moblie considered an authorized dealer for iphones?

  • Linda

    My husband had an Iphone 3G. He wanted a 3GS. Only I was due for an upgrade. We purchased the GS for me with my number. Then he gave me his 3g and kept the 3gs. We switched SIM cards. The SIM cards do look a little different with the etching(?). Has worked; but his battery runs down quickly, and 3 days later, a couple of times his phone just locked up and said “searching” for network. So, are these phones/SIM compatible or is the 3G card screwing up his 3GS phone? What is your recommendation? Thanks.

  • sammy

    You need a Wifi internet connection to update cydia as i did before to unlock it…

  • Raza Ali

    Can anyone help me plz?

    Yesterday I refresh my iphone through jailbreak and it’s done but after that my Card is still not accepting it shows “NO SERVICE” does anyone has idea about this?

    I have done all the steps as mentioned above except below two:
    1. Add the repo repo666.yellowsn0w.com to Cydia or Icy. That last “o” is actually the number zero “0”.
    2. Search for ‘yellowsn0w’ in cydia or icy and install ultrasn0w.

    Does it require ?

  • jhon

    hi… i dont know what happend to my iphone 16gb.. when i turn it on…there only comes pine apple logo….it stops there…nothing else appear…can any one help me plz…what to do..??

  • kirkome

    I have been researching the unlock process for my iphone. i recently purchased it and I am wondering if I can jailbreak with pwnage and use a rebel sim card to unlock? my iphone is on firmware 2.2.1 with the baseband 2.30.03. just wondering if this would be a solution to unlocking my phone to operate on T-Mobile. thanks

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  • Cena

    Wow its an exciting news… I hope I wll be able to unlock 3GS with it too… thanks!

  • louise

    hi my boyfriend has brought a 2 g iphone but hes on 3network contract would he be able toput is sim card into to the iphone if so could anyone tell me how to to it plz only its saying incorrect sim thx

  • Swapnil

    Can I unlock iphone purchased in U.S. and use in India with any sim cards?
    Please help me out

  • Nico

    Hi, i have been to the US in march for work and bought an iPhone 3G, firmware 3.1.3. have jailbreaked it with SnowBreeze and unlocked with blackra1n and then tried ultrasnow as well, i still get no service. What can i do to enable for GSM networks 9vodacom) in South Africa? Please help

  • Suleiman

    guy's i have a 3gs iphone and i cant use it at all it is locked so some help please

  • Guest

    Has anyone manage to unlock Iphone 3GS with 3.1.3 OS and 05.12.01 firmware?

    • Grandmaster Flash

      yeah i have, with GoPhone, trying to find cheaper service than ATT and Tracphone uses GSM, but ties their cards to IMEI numbers of the phones they sell them with. You have to do major spoofing of the tracphone’s IMEI to get the tracphone card to think it’s in it proper phone. It looks like so far the only pre-paid service that work easily on and unlocked phone are ATT GoPhone and T-Mobile. Currently looking for others.

  • Dave

    my firmware is version 2.30.03 so does the unlock work so i can use my iphone with any sim card? the phone is running on 2.2.1 5h11 and was originally on at&t.


  • Brodie Howarth

    can some one help me i am realy bad at phone lol
    i have bought a phone of ebay and its locked it is only letting me do emergency calls and that it
    woundering if anyone one can help me please many thank

  • Natalie

    hey guys, i’m currently in jerusalem israel for a few months and have my iphone 3g with me that i have an at&t plan with, i put the plan on hold while im gone but was thinking about unlocking it and buying a sim card here for some pre-paid minutes but someone told me if I do that then my phone will not work with at&t once i get back to the states…is this true?

  • NCISwolf

    does the iphone work with any sin card if jail breaked?

  • Didn’t work!
    Did everything as told. (iPhone 3G on 4.1 iOS, Jailbroken with Pwnage Tool).
    When added the source to Cydia, got an error about a bad source and that’s it.

  • Mani_mirza10

    i have an iphone 2g 3.1.3 .. i installed new software 3.1.3 thru itunes and then it says that the sim card is not recognised and it says to connect to itunes and the phone is not going beyond emergency calls,,,, im in pakistan … any one help me please ….

    • Milos_cosa

      you got to have the at.t sim card to unlock it

    • Milos_cosa

      you got to have the at.t sim card to unlock it

  • S_urena

    my unlock iphone i try to upgrade now it dont want to read my sim card?? what i do??

  • Amandaedgar41

    once its unlocked can u use any sim card in it

  • Tek_456

    I can not unlock my Iphone which is received from usa

  • sab

    i receive an iphone 3g from canada..but lock i cant use any sim card im here in taiwan what am i gonna do,,,modem firmware is 05.16.02..thanks..someone gonna help

  • This is great. We all buy iPhone at cheap price from network provider and then unlock it.

  • nikhil

    i ve restore my iphone 3G  4.1.1 using redsnow….now its showing no sim ,even after inserting it…it s asking me for knwn carrier ….pls help me
    email me..nikkuale@gmail.com

    • komal

      nikhil! did you get the solution to your problem?? actually me too have the same.. 🙁

  • Whatfor

    USELESS … tutorial TO OLD!

  • Boibato_13

    me to im in the same problem please help me my email is boibato_13@yahoo.com

  • Basyi geffin

    Guys, it’s 2009 posts! Nowadays, if you want to unlock iPhone, simply search “factory unlock senseiPhone” and you’ll be able to unlock ALMOST any iPhones!

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