You can pay in up to £20,000 each tax year, and you can split your allowance across the different types of ISA. For example, you could put £4,000 in a Lifetime ISA (this is the yearly maximum), £11,000 in a Stocks & Shares ISA and £5,000 in a Cash ISA, or any combination you like. You can also pay up to £9,000 per year into a Junior ISA on behalf of a child.