The HTC One 4.2.2 Jelly Bean update started rolling out in Europe last week, and now HTC has announced on Twitter today that the update is being rolled out in the UK.
The 4.2.2. update for the #HTCOne started rolling out in the UK from today. Download it now: Settings > About > Software Updates > Check now
— HTC UK (@HTC_UK) July 15, 2013
The Android 4.2.2 Jelly Bean update should be available for your HTC One as of now in the UK, you can check to see if it is available via the settings menu on your device.
Source HTC / Twitter