The Xperia C is Sony’s first Xperia smartphone that is powered by a MediaTek chipset. The Xperia C is no slouch given the inclusion of the MediaTek MTK6589 chipset comprising a 1.2 GHz quad-core processor and IMG SGX544 graphics. However, if you were hoping to try, or develop, some custom ROMs for the handset, then your journey is unlikely to be fruitful.
Sony has confirmed to us that the Xperia C bootloader cannot be unlocked and that there are no plans to unlock it going forward. The reason behind this is a simple one, the inclusion of the MediaTek chipset means it will have a different loader and therefore the unlock architecture is not supported.
You can see the evidence below on our resident Xperia C and the handset does not make the list of supported phones on the Sony’s Unlock Bootloader website either. The use of a MediaTek SoC in more Xperia phones next year could mean that Sony may provide the ability for users to unlock the bootloader, but this won’t be the case for the Xperia C.