If you have an ISA - or several ISAs - then you may have heard there are some changes on the way. We’ve put together an article to help you understand which ISA rules are changing, which are staying the same, and whether you need to do anything.
What is the current ISA allowance?
The overall annual deposit allowance for adult ISAs is £20,000. This is for the 2026/27 tax year which runs from 6 April 2026 to 5 April 2027.
The ISA allowance refers to how much money you can deposit into ISAs in a tax year. You can split the £20,000 allowance across different types of ISAs, like cash ISAs and stocks and shares ISAs.
The allowance for children’s ISAs (Junior ISAs) is currently £9,000 per child.
How ISA allowances work
While there’s a limit on how much you can deposit into ISAs each tax year, there’s no cap on the total value you can accumulate over time. For example, if you pay the maximum of £20,000 into ISAs each tax year for three years, you'll have invested £60,000, which remains, free from UK Income Tax and Capital Gains Tax while you keep the money in ISAs.
Your ISA allowances do not roll over, so if you deposit £10,000 one year, you cannot deposit £30,000 the next year to make up the difference.
Here’s what’s changing in 2027
From 6 April 2027 - the start of the 2027/28 tax year - you’ll have a £12,000 cash ISA allowance if you’re aged under 65.
You could still pay up to £8,000 (the remaining portion of the overall £20,000 allowance) into stocks and shares ISAs or other eligible ISAs. This change will only apply to new deposits you make from April 2027 and won’t have any impact on savings you’ve already contributed to cash ISAs.
If you’re aged 65 or over, then you are unaffected by this change and your cash ISA allowance will remain at £20,000 for the 2027/28 tax year. If you’re turning 65 part-way through the 2027/28 tax year, the new rules on maximum deposits will be clarified after an industry consultation in 2026.
| 2026/27 Tax Year | 2027/28 Tax Year |
|---|---|---|
| Overall ISA allowance | £20,000 | £20,000 |
| Cash ISA allowance (under 65s) | Up to £20,000 | Capped at £12,000 |
| Cash ISA allowance (aged 65 and over) | Up to £20,000 | Up to £20,000 |
| Stocks and shares ISA allowance | Up to £20,000 | Up to £20,000 |
| Junior ISA allowance | £9,000 | £9,000 |
What to do before the next tax year begins
Nothing is changing until April 2027, so you don’t need to take any immediate action.
Learn more about ISAs
If you’d like to know more about ISAs, including the different types, please read our 'What is an ISA?' article. NS&I offer a cash ISA with a variable interest rate called a Direct ISA
Saving with NS&I
NS&I is the UK government savings bank. We believe that everyone should be able to save confidently for what matters to them. If you’re ready to start your saving journey, explore our range of products and join the millions of people already saving with us.
