Autumn Budget on 28 October 2026. The Chancellor could change some of these rules. We will re-check this page in the week after the Budget and update the date below.
In 30 seconds
- Until 5 April 2027 you can put up to £20,000 into cash ISAs; from 6 April 2027, under-65s can put only £12,000.
- Money already in a cash ISA stays tax-free.
- Worth most to higher-rate taxpayers with large cash savings above their Personal Savings Allowance.
- If you won't need the money for five years or more, investing may suit you better.
Key figures
The deadline in one sentence
Until 5 April 2027 you can put up to £20,000 into cash ISAs this tax year. From 6 April 2027, if you are under 65, only £12,000 of each year's allowance can go into cash. Money you put in before the change stays in your cash ISA, tax-free, for as long as you like.
So if you keep a lot of savings in cash, using this year's full £20,000 is the last chance to shelter that much in cash in a single year.
Who this matters for
| You are… | Does the deadline matter? |
|---|---|
| Under 65 with more than £12,000 a year to save in cash | Yes. This year is the last with a £20,000 cash limit. |
| Under 65, saving less than £12,000 a year | No. The new limit won't restrict you. |
| Turning 65 during the 2027/28 tax year, or already 65 | No. You keep the £20,000 cash limit. |
| A basic-rate taxpayer earning less than £1,000 of interest a year outside ISAs | Less than you might think: that interest is already tax-free under the Personal Savings Allowance. |
What it is worth: the tax you avoid
The benefit of a cash ISA is that the interest is tax-free. Outside an ISA, interest above your Personal Savings Allowance (£1,000 for basic-rate taxpayers, £500 for higher-rate, nothing for additional-rate) is taxed. From April 2027 those rates rise to 22%, 42% and 47%.
Here is the yearly tax on interest from £8,000, the extra amount you can't put into cash from 2027, at an interest rate of 4%, assuming your Personal Savings Allowance is already used by other savings:
| Your tax band from April 2027 | Interest on £8,000 at 4% | Tax outside an ISA |
|---|---|---|
| Basic rate (22%) | £320 | £70.40 |
| Higher rate (42%) | £320 | £134.40 |
| Additional rate (47%) | £320 | £150.40 |
That is the saving each year the money stays sheltered, so it grows over time. For higher-rate taxpayers with large cash savings, it adds up.
Before you rush to pay in
- Check whether you really need that much in cash. The government's aim is to encourage investing for the long term. Money you won't need for five years or more may be better invested, for example in a stocks and shares ISA, which keeps its full £20,000 limit.
- Compare rates. A cash ISA paying much less than a taxable account can still lose out for a basic-rate taxpayer whose interest is covered by the Personal Savings Allowance.
- Check flexibility. Fixed-rate cash ISAs can charge penalties for early access. Easy-access ones pay less.
- Don't borrow to do it. The tax saving is small compared with the cost of debt.
After 6 April 2027: what changes for transfers
Under-65s won't be able to move money from a stocks and shares ISA into a cash ISA. If you want cash later, money already in a cash ISA keeps that flexibility. And if you hold uninvested cash inside a stocks and shares ISA, interest on it will face a flat 22% charge.
The full rules are in our guide to the £12,000 cash ISA limit. If you are weighing cash against a pension for retirement, see ISA or pension.
Common questions
If I fill my cash ISA now, can I keep it there after 2027?
Yes. The new limit only applies to new money paid in from 2027/28. Existing cash ISA savings stay where they are, tax-free.
Can I split this year's allowance between cash and stocks?
Yes. The £20,000 can be split across cash, stocks and shares, Innovative Finance and Lifetime ISAs, with the Lifetime ISA capped at £4,000.
Sources
This guide is general information, not personal financial advice. Rules can change and your situation may differ. For free, impartial help, contact MoneyHelper, or speak to a regulated financial adviser.
