I bought a flat in 2001, lived in it until 2004 and then started renting it out whilst I moved to another part of the country and rented there. I've recently put the flat on the market. If I get the full asking price, I will have made a profit of over £100,000 on it. Does this mean I will have to pay captial gains tax (and what % is that?). Also, if I am liable for a huge amount of tax, is it possible to avoid it by moving back into it for a while, and if so, how long?