Surprise, surprise: The Xperia Z1s for T-Mobile has a locked bootloader

There was some hope from owners of the Sony Xperia Z1s (C6916), that T-Mobile US would not lock the bootloader like it had previously done for the Xperia Z (C6606). Unfortunately that is not the case, the Xperia Z1s bootloader cannot be unlocked as users have begun to find out. Initially, this will limit those who want to root their handsets or try a custom ROM, although there may be ways around this at some point down the road. This is unlikely to affect the majority or prospective owners, but it’s worth considering if you’ve enjoyed testing custom ROMs in the past.

Thanks Jonathan!