Unlocking the boot loader allows you to put custom ROMs on your device. However, we recommend standard users not to unlock the boot loader, as it is not needed. We are proud to deliver great software experiences through our rigorously tested and official software releases. If you are not familiar with this technology, then you shouldn’t unlock the boot loader.
Please note that you may void the warranty of your device and/or any warranty from your operator if you unlock the boot loader. See your device's warranty statement for details. Additionally, due to the modified device software, Sony’s repair network will likely have to replace key components before it can properly test, repair and verify your device using our repair tools and software. Consequently, if Sony performs a warranty repair, Sony will likely charge you a significant service fee for the additional costs caused by your modification of the software.
If you unlock the boot loader and then flash a custom unsigned ROM to your device , the custom unsigned ROM will not have gone through the thorough tests that we run for each device and software version that we release. Sony can then no longer guarantee the full functionality of your device, and will not be responsible for any unsigned custom software being flashed to the device after the boot loader is unlocked.
Furthermore, the custom unsigned ROM might not work properly on your device. Certain functions may cease to work, and the performance of the device might not be ideal. You might damage your device permanently. In the worst case, unlocking the boot loader will cause physical injuries or material damage, for example, due to the device overheating. Certain pre-loaded content on your device may also be inaccessible due to the removal of DRM security keys and the secure user data partition while unlocking the boot loader.
For Xperia™ devices released 2013 or later (for example Xperia™ Z and Xperia™ ZL), the SD card of your device will be formatted and you will lose all content (for example photos, music, videos) when you unlock the boot loader.