Capital Gains tax is payable on the profit of any asset you ‘dispose of’ which has increased in value since purchase. There are exemptions and reliefs which can reduce your CGT liability helping you to be as tax efficient as possible.
You will need to pay CGT on ‘disposal’ of an asset if your total taxable gains are above the CGT threshold in the applicable year. This year 2017/18 the allowance is: £11,300.
An understandably confusing area, we can advise you on reducing your liability longer term, make use of all available exemptions and reliefs and complete your HMRC documentation upon ‘disposal’ of any appropriate assets.