An unlockable bootloader is the key to tinkering with your Android device. People who want to flash custom ROMs, kernels or tweak with their devices at an advanced level need to first unlock the bootloader. Its very easy to do that if you have a developer, Google Play edition or a Nexus device. Not all OEMs ship their devices with unlockable bootloaders, some cater to carriers’ demands and lock them down for good. It has been discovered that T-Mobile Sony Xperia Z1s bootloader unlock is not possible, simply because this smartphone is not shipping with an unlockable bootloader.
It goes without saying that anyone who buys this smartphone won’t be able to tinker with it, flashing custom ROMs is out of the question until a solution has been developed or if T-Mobile decides to rectify this by issuing an update. Its ironic that for a carrier that’s defying the norms of the wireless carrier industry, T-Mobile has gone down a very traditional route that carriers take to stop customers from tinkering with their devices. There aren’t many differences between the Xperia Z1 and the T-Mobile exclusive Z1s, however the former does come with an unlockable bootloader which can be unlocked by obtaining an unlock key from Sony’s developer portal and applying it via fastboot. So if tinkering with the device is important to you, you would probably be better off without the Z1s at this point in time.