To check for the update, you can either use PC companion or go to settings > about phone > system updates on your handset.
The Xperia Z launched with Android 4.1.2 so the update won’t bring huge changes, but it should bring a few performance enhancements and new features.
The most noticeable difference between Android 4.1.2 and Android 4.2.2 is the ability to add lock screen widgets which will be a welcome addition to the Xperia Z experience.
At the moment we await confirmation as to whether or not the update has begun rolling out to UK devices. However we can as usual we can expect the SIM-free/international version of the Xperia Z to receive the update before carrier models once it is available here in the UK.
Let us know in the comments if you have received the update for your device.