To began reading this post first you need to know that all methods which are given here have two problems. First not all of tham are free. Even those which are free can't be used on some baseband as 04.12.01 on iPhone 4 running iOS 5.1.1. For that model there is the paid method. But, as for me, this paid method is too expensive, so I have something for you - cheap and legit at the same time. You can try iPhone IMEI unlocking service that can be used on all iPhone baseband, iOS and networks. 8/16/2012 - Update: Dear users, its seam for now there is only IMEI unlock solution for those who stacked on 04.11.08 - 04.12.01 basebands. The only problem there are no free IMEI services on the web, but we cached out DigitalUnlocking.com website who seems to have the cheapest prices starting from $6 depends on the carrier your device was locked to. Since we are available to jailbreak the latest iOS with Absinthe 2.x it’s time to think on how to unlock baseband iPhone 4 04.12.01 iOS 5.1.1 or iPhone 3GS as well. If you have already jailbroken your device or plan to do it in the nearest future – read on and find out which are those unlocking solutions. Also if your iPhone 4 is on 04.11.08/04.12.01 you can use this link to see others way to unlock it. May be there you will find your way. First of all, there are three methods for you to unlock your iPhone 4 or iPhone 3GS on latest firmware. They all depend on your baseband versions. The first one is Ultarsn0w fixer 5.1.1.

How to unlock iPhone 4/3GS iOS 5.1.1 with Ultarsn0w fixer 5.1.1:

Note: ONLY following basebands can be unlocked using this tool:

• iPhone 4 — Baseband 01.59.00
• iPhone 3GS — Baseband 04.26.08
• iPhone 3GS — Baseband 05.11.07
• iPhone 3GS — Baseband 05.12.01
• iPhone 3GS — Baseband 05.13.04
• iPhone 3GS — Baseband 06.15.00

Step One: Jailbreak untethered with Absinthe or Sn0wbreeze. Step Two: Run Cydia, go to Manage->Sources Step Three: Add this repo: http://repo.iparelhos.com/ Step Four: Go to Search and type in ultrasn0w 1.2.5 and tap Install. Step Five: Search for Ultarsn0w fixer 5.1.1. Install it. That’s it, you have successfully unlocked your iPhone 4/iPhone 3GS on Ultarsn0w fixer 5.1.1 supported baseband and iOS 5.1.1. The second way for you to unlock iPhone 4 4.12.01 (as well) is to use your saved SAM ticket. This method works for all devices including unlocking iPhone 4 04.12.01 iOS 5.1.1 as long as you have your activation ticket saved.

Unlock iPhone 4 with SAM 5.1.1:

Step One: Jailbreak untethered with Absinthe or Sn0wbreeze. Step Two: Run Cydia and install the latest version of SAM (0.1.15-1) Step Three: Launch the app, go to Utilities and tap ‘Revert Lockdownd to Stock’. That will put your Lockdown folder (where the activation ticket is saved) is status quo position. Note: My iPhone 4 caught network right after I did that. If your didn’t – please proceed. Step Four: Put the previously saved activation Lockdown folder back to /var/root/Library/Lockdown Step Five: Reboot your phone. Step Six: Now you can delete SAM if you want to. And finally the last method that can unlock your iPhone iOS 5.1.1 almost on any baseband.

Unlock iPhone 4 iOS 5.1.1 with Gevey SIM:

We have plenty of tutorials on how to unlock your iPhone 4/4S with Gevey SIM. Nothing has changed with iOS 5.1.1 release and all those cards work perfectly with the new Apple’s firmware. Check this link to find a solution for you. As you can see there’s a way to unlock iPhone 4 04.12.01 iOS 5.1.1, but if you were lucky and fast enough to perform your SAM unlock during the week he worked. As soon as you have your ticket saved and stick to the only SIM card – you’re out of danger. Please let us know how those methods worked for you in the comments under the post or on social networks.