Can I Unlock iPhone 4S on iOS 5 Using Ultrasn0w?

Hello Romano, you are right. The iPhone Dev-Team, Chronic-Dev Team, as well as the other iOS hacking teams are actively working to get an untethered or tethered jailbreak for iPhone 4S on iOS 5 firmware. Thought there’s not much info present regarding this but it is widely expected that the same jailbreak tool will also work on other iOS devices, such as the iPhone 4 (CDMA and GSM), iPhone 3GS, iPad 1, iPod Touch 4G, iPod Touch 3G, and iPad 2. Regarding the iPhone 4S unlock, it seems like we are gonna get a new iPhone unlocking solution soon. MuscleNerd of the iPhone Dev-Team has just announced via Twitter that the unlocking solution for the iPhone 4S “in the works”. And unlike the jailbreak for iPhone 4S, according to MuscleNerd’s tweet (please see the image posted below), the new unlock solution will only work on iPhone 4S.

So, will you be able to unlock using Ultrasn0w? As far as I know, Ultrasn0w 1.2.3 / 1.2.4 will only work on iPhone 3GS, iPhone 3G, and iPhone 4 (baseband 01.59.00). Not unless if the Dev-Team will release a new version of Ultrasn0w.

Anyway, before you get an unlock, you should jailbreak your iPhone 4S first – which is not possible at the moment. You should note that Ultrasn0w or any software-based unlock will require an untethered jailbreak in order to work accordingly. So, you should wait for iPhone Dev-Team for the iOS 5 untethered jailbreak as well as for the iPhone 4S unlock.

On the other hand, you can check this blog post on how to unlock iPhone 4S even without jailbreaking or using Ultrasn0w.

Note: Please STAY AWAY from iOS 5.0.1 and iOS 5.1 software update.