I purchased a flat some 18 years ago in the UK, because I was going to move abroad. This property has been let for this period. I now wish to return to the UK and live in this property as my main residence. What would my tax liability be?  

Arthur Weller replies:  

As you are not disposing of the flat but simply moving into it after a period of renting it out, there is no tax liability. However, if and when you eventually sell the flat, you will get relief for the period you have lived in it as your main residence. For example, suppose you move into the flat in 2023 and sell in 2033. Then 10/30 of the total capital gain (i.e., from 2003 to 2033) will be exempt from capital gains tax due to principal private residence relief.