I have owned a property for 40 years, lived in it for 30 years and rented it out for ten years. The initial price paid was £200,000 and I sold it for £600,000. Is there any capital gains tax (CGT) to pay, and, if yes, how much?

Your capital gain is £400,000, which, spread over 40 years, equates to £10,000 per year. The first 30 years are exempt, as are the last 1.5 years. So you have a taxable capital gain for the remaining 8.5 years, which equates to £85,000. Since you rented out the house for those years, you can claim the letting exemption of £40,000, reducing your gain to £45,000. If you have the CGT annual exemption of £11,100 available (for 2016/17), this will reduce the taxable gain to £33,900. Any part of the gain falling within your basic rate band is taxable at 18%, and any part above is taxable at 28% (I have made an assumption you are a single person, but if you are a married couple, the calculations are different).