Before 6 April 2018, individuals may invest in companies that qualify under the Enterprise Investment Scheme (EIS) and treat that investment as having been made in 2016/17. The tax relief is 30% of the amount invested. So a £20,000 investment can reduce the 2016/17 tax liability by £6,000. Investing in a Seed EIS qualifying company is even better as there is a 50% tax relief. Such companies tend to be riskier than EIS qualifying companies. You should therefore obtain specialist advice from an IFA if you are considering such investments.
Investing in an EIS qualifying company can also enable you to defer capital gains tax. In order to do so you must reinvest the amount of the gain within the 3 years following the date of the disposal giving rise to the gain. (The investment could also be within 12 months prior to the disposal).