Hey peeps I took this from Sony UK support site:
Latest available software
You may already have the latest software, depending on the date of purchase. Software updates are released at different times depending on operator and/or country. Therefore, we cannot give you an exact date for when a specific update will be available for your device.
Android version: Google Android 4.4 (Kitkat)
Latest available software: 17.1.1.A.0.402
Release started: 2014-05-23
To find your device’s current software version:
Settings > About phone > Build number / version
SO it seems that .402 is available in the UK.
Hope this helps