If you intend to purchase a house one day, you need to know about the Lifetime ISA. The Lifetime ISA is a tax-free individual savings account that can, and should only, be used for purchasing a house, withdrawing after retirement (your 60th birthday), or if you are terminally ill with less than 12 months to live. The UK government will add a 25% bonus onto your savings up to £4,000 every tax year.