FASVIG support the concept of a common high Transition Altitude (TA) throughout the UK. See FASVIP VEE.10
The CAA has now published Information Notice IN–2015/104, which provides advanced notice of a consultation on a UK-wide harmonised Transition Altitude (TA) of 18,000 ft.
1.1 The CAA will be launching a consultation on 23 November 2015 on a UK-wide harmonised Transition Altitude (TA) of 18,000 ft designed to enhance efficiency, both inside and outside controlled airspace, through standardisation of airspace and altimeter setting procedures. A harmonised TA of 18,000 ft would enable future safety, environmental and economic benefits to be realised through improvements to the vertical profiles of aircraft arrivals and departures in the London and Scottish Flight Information Regions (FIRs). It would also serve as a platform for future airspace and operating concepts through programmes such as Single European Sky (SES), SES Air Traffic Management Research (SESAR), Future Airspace Strategy (FAS) and the UK/Ireland Functional Airspace Block (FAB).
Read the full CAA Information Notice