It's even more complicated because from 2012 (I think) you are liable for UK capital gains on a percentage. I have just sold my UK house.. I know I had to inform HMRC and I did a calculation that said I owed them £750 on the increase in value from the day this law came into force.. I now have to submit something on this years tax form for the French impots but I have no idea how that is worked out. I am getting some tax advice so will let you know what I find out.