Introduction to Unlocking the iPhone 4
The iPhone 4 is the single fastest-selling smartphone in history. It really needs no introduction. Unfortunately, it is only sold locked on select carriers worldwide which means if you need to travel out of the country or want to use a different GSM carrier, you’re out of luck. But today, we will show you how to SIM unlock your iPhone so that you can use any GSM SIM card to make and receive calls and messages, and access the internet through your data plan if you have one. One advantage of having an unlocked iPhone is that it will already be jailbroken for some really cool jailbroken apps, you will be able to use a different service provider (T-Mobile instead of AT&T Wireless in the US), and it increases the phone’s resale value.
The process is 100% legal and fully reversible via an iTunes restore should Apple need to service your phone in the future.
What You Will Need to Unlock Your iPhone
* iPhone 4 running iOS 4.0.1 (or 4.0) and the 01.59.00 baseband
* Alternatively, an iPhone 3GS or 3G with the 04.26.08, 05.11.07, 05.12.01, 05.13.04, or iPad’s 06.15.00 basebands
For those that have upgraded to iOS 4.1 or 4.2.1, you will need to downgrade iOS to 4.0.1 for this unlock to work. This can be done, but an unlock for 4.1/4.2.1 should be out soon, so stay tuned! In the meantime, you can still jailbreak your 4.2.1 iPhone 4 with the RedSn0w tool for both Windows and Mac.
If you are unsure of your baseband, you can easily find it by going to Settings > General > About > Model Firmware (your iPhone’s current baseband).
Jailbreaking Your iPhone 4
jailbreakmeThe easiest method of jailbreaking your iPhone running 4.0 or 4.0.1 is to use JailbreakMe. It is as simple as visiting the jailbreakme.com on your iPhone’s browser and sliding the tab to initiate the jailbreak. It only takes a couple of minutes and will have your phone rooted (unlocked) in a matter of minutes. Of course, there are other methods of jailbreaking an iPhone, but this is the easiest for iOS 4.0.1 and the one I have used myself.
Unlocking Your iPhone 4 (or 3GS or 3G)
ultrasn0w cydia repository repoNow on to the real reason you’re here. Now that you have your iPhone’s phone system unlocked with full root access, you can now unlock the phone to be used with any SIM card. To do this, you will need to bring up Cydia, the new app that was installed when you jailbroke your iPhone.
1. Open Cydia.
2. Go to the manage tab, tap sources > edit (top right) > Add (top left) > Enter http://repo666.ultrasn0w.com (note the 0 is the number zero) > Add Source.
3. Tap Return to Cydia and tap the Search tab and search for ultrasn0w. Once you begin typing, it should begin to come up.
4. Tap on the ultrasn0w app page and tap install. This install process will take a few minutes and once it is finished you will be prompted to reboot your device.
ultrasn0w appUpon rebooting, your iPhone will be unlocked. There will be no indication that it is unlocked so have a foreign or a different SIM card handy to check that it is indeed unlocked!
Considerations of an Unlocked iPhone 4
Enjoy your unshackled freedom! Take care not to update your iPhone for this will most certainly break the jailbreak and definitely cause you to lose your unlock. Another consideration for having an unlocked iPhone 4 is the phone’s Micro-SIM card which is only found on a few devices. To use your iPhone 4 with another SIM card, you will probably have to trim the SIM card to fit in the iPhone 4’s tiny slot.