If you moved out of your old house 2 years ago, then one year of your ownership is liable to CGT from what I know. Sale of a PPR is exempt from CGT provided that you've lived in it the whole time plus you get 12-months "grace period" after you've moved out. So, if you owned the house for e.g. 3 years and moved out after one year, you'd owe CGT on 33% of the profit (you determine profit as the diff between purchase price and sale price). You can also deduct relevant expenses (e.g. auctioneer's fees) and your annual CGT allowance prior to calculating CGT.