How to unlock your 3G iPhone for free

by Leo PangLeo Pang on 1230850507|%e %B %Y
rating: 0, tags: 3g devteam free how-to iphone software unlock


Warning: This only works for v2.2, not earlier or later versions.

DevTeam announced their software 3G iPhone unlock as promised on New Year's eve. It's not exactly as what rumor said, it's not for iPhone firmware 2.1, but it's actually for the latest version 2.2. Now if you want to use your 3G iPhone on other carrier's network, you can do it with their software. You don't need any hardware to do so, like those ultra thin SIM cards, and the best of all, it's free.

Their code only works on iPhone firmware 2.2, so what you need to do is to first upgrade your iPhone to the latest version 2.2 with iTune. Once you are on 2.2, then you have to jailbreak your iPhone. If you don't know have to jailbreak, look at our Jaibreak section for instructions.


  1. Go to Cydia and install this new source: (note that snow is spelled with a zero, not an “o”). To install a new source in Cydia, go to Manage > Sources > Edit > Add, then type in the source and tap “Add Source”.
  2. Once the source has been added, tap “Return To Cydia”, then tap “Done”.
  3. Now tap “ from the list of sources “Entered By Users”.
  4. Select Yellow Sn0w, then tap install and confirm.
  5. Once the installation had been successfully completed, return to Cydia.
  6. Reboot your iPhone
  7. Insert whatever SIM card you want! Wait a few seconds and you should be good.


This is very simple and straight forward. The jailbreak process is actually more complicated.


You should read the DevTeam's blog. They are the guys who developed this 3G iPhone software unlock.

The following is copied from their site:


  • The unlock works exclusively with baseband 02.28.00. This baseband is provided by the latest firmware update (2.2) from Apple. You’ll need to upgrade to this release using iTunes and then use QuickPwn to activate etc. There are plenty of tutorials about this on iclarified, bigboss, and other established tutorial sites. Because it works on 02.28.00, it is available to everyone on the planet. This means we don’t need to unnecessarily expose holes in earlier basebands, which is an important concern.
  • The application is a small daemon that is launched on boot. It injects the payload at boot and also whenever there is a baseband reset. You won’t notice anything about it other than that your third-party sim now works. It’s a small program and unobtrusive. There is no GUI (this is by design).
  • You can add the application using the sources outlined below (coming soon). There are Cydia and Installer sources available, so use whichever you are comfortable using.
  • yellowsn0w is completely removable through Cydia, the command line, and iTunes.


  • There is a known issue with SIM cards that have STK (SIM Toolkit) application menus. These menus are usually items such as “top up” “get credit” “lotto numbers” etc. These menu items confuse the application sometimes. Removing and reinserting the SIM once after reboot (give it about 10 secs 60 seconds (with v0.9.1) after you see the slide to unlock widget) fixes this issue. We’re working on a better fix.
  • For those of you using SIM cards without STK menus, the application has some optional arguments that will make the unlock much faster for you. So either experiment on your own (use “yellowsn0w -h” for usage) or wait for a customization writeup.
  • After you install yellowsn0w via Cydia, you should return to the Cydia main menu then reboot your iPhone with the 3rd party SIM installed. Wait for the slide to unlock screen, then wait 10 or 15 secs more. If you don’t see your carrier name pop up, then remove your SIM, reinsert it, and wait 10 secs more. This is the step we’ll be working on eliminating next.


  • The application is version 0.9 0.9.1. This is considered beta software, you use it at your own risk. You know the score.
  • The application is released on a non-commerical basis. Please do not accept pirates and scummy ripoffs of this software. We license this software for single use and in a non-commerical environment (meaning you can’t charge for it). The techniques and methods used are not to be used by third party companies. We are watching you Jody…we won’t be so forgiving this time.
  • Direct linking to the repository URLs is prohibited, please only link to this post. We will be checking referers.
  • Happy 2009 and enjoy!

The iPhone 3G is used all over the world with all sorts of SIM cards, and we almost certainly will see untested and unexpected situations. If the soft unlock doesn’t work for you on day 1 (literally day 1, of 2009!) then please don’t panic or be impatient. This is new territory for everyone, so enjoy the ride as much as you can :)



  1. Soon you’ll see yellowsn0w 0.9.1 in the repos. It uses a much longer delay to let your SIM card initialize. If you have problems with 0.9.0, try this one and wait a full minute after you see homescreen, then reinsert sim card. We need both success and failure reports to tune this across the world, so please be patient (but please also report result!)
  2. If you are in the U.S. and are trying this with T-Mobile, you must turn off the 3G switch in Settings. Also if you are good with the command line, you can make it much easier by adding the line <string>-q</string> right after the /usr/bin/yellowsn0w line in /System/Library/LaunchDaemons/org.iphone-dev.yellowsn0w.plist (that’s and advanced tip, hopefully someone will make a boosprefs type of tool for it)
  3. No PIN support yet. Remember how we said this was beta? Well we’re still working out the flow for SIMs with PINs enabled. Please disable any PIN you may have on that SIM before trying yellowsn0w, for now.
  4. The unlock will silently quit on anything other than baseband 02.28.00. It detects the wrong version and just quits to avoid any damage. Please double check your Modem Firmware setting in Settings->General->About.
  5. For ankle-biters that are pointlessly reversing the application the source is here all open, but remember Jody, we are watching you.
  6. Thanks for the kind words Stephen

Things You'll Need

You just need your iPhone, your computer with iTune to complete software 3G iPhone unlock.

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