How to unlock iPhone 4 on iOS 5.1.1 with Baseband 04.12.05
0
leader • February 16, 2013 at 3:25pm
Is there a software solution or a way to downgrade the baseband from 04.12.05 to 01.59.00 to unlock an iPhone 4 running iOS 5.1.1?
Answers
0
iClarified • January 12, 2026 at 7:06pm
There is no software-based unlock (like Ultrasn0w) for the 04.12.05 baseband on the iPhone 4. Additionally, it is not possible to downgrade the baseband on an iPhone 4. Software unlocks were only available for the very early 01.59.00 baseband version. The only way to unlock an iPhone 4 with this baseband is through an official IMEI factory unlock from the original carrier or a third-party unlocking service.