There is a limit set by the UK government on how much you can put into your tax-free Individual Savings Accounts (ISAs) each tax year. That sum is called an ISA allowance. For the 2021/2022 tax year, the allowance has been set at £20,000.
You can invest all of your allowance in one type of ISA or split it across different types. You can only pay into one of each type of ISA in each tax year.
Bear in mind that with a Lifetime ISA, the maximum limit of investment is set at £4,000 each tax year, which is deducted from your annual allowance. This means if you are saving the full £4,000 in a Lifetime ISA, you have £16,000 to invest in other types of ISAs. The limits are set for all ISAs combined, across several accounts with one or more providers in the same tax year, all within the same ISA wrapper.
Keep in mind that any unused allowance does not roll over to the next tax year, so if you don’t use it, you will lose it. For example, if you put £10,000 into a stocks and shares ISA and £5,000 into a cash ISA, you will be able to claim the ISA tax advantages on £15,000, not the full yearly allowance, and you will not be able to roll the extra £5,000 over to next year. You will get a new allowance on 6 April of each year, which is the start of the tax year, but you will not be able to add any money to the old ISA from the previous tax year.
If you want to move your old ISAs from one provider to another using the official channel, it will not impact your current year’s allowance.