From April 2017, those under the age of 40 can contribute to a lifetime ISA to the sum of £4,000 each tax year for the purpose of purchasing a first home or for retirement. At the end of each tax year the government will provide a 25% bonus on the contributions, so if you save £4,000 in the tax year the bonus will be £1,000. Savers will be able to make Lifetime ISA contributions and receive a bonus from the age of 18