From 6 April 2027, anyone under 65 who wants to save in a cash ISA will be able to put no more than £12,000 a year into one. The overall annual ISA allowance stays at £20,000, so the remaining £8,000 can go only into other types of ISA, such as stocks and shares. Savers aged 65 and over keep the full £20,000 cash limit. The change, announced at the Autumn Budget in November 2025, is now backed by detailed government papers published this year, which also set out rules designed to stop people sidestepping the new cap.
For the millions of people who use cash ISAs for tax-free interest, the practical question is what this changes, when, and what is still unknown. This article sets out what the government has published, what it says the policy is for, and where the gaps remain.
In short
- The change: from 6 April 2027, the annual cash ISA limit for people under 65 falls to £12,000, within the overall £20,000 ISA allowance.
- Who is exempt: people aged 65 and over keep a £20,000 cash ISA limit.
- The stated aim: to encourage retail investment and support better returns for savers, according to the government.
- New rules: transfers from non-cash ISAs into cash ISAs will not be permitted for under-65s, and a flat 22% charge will apply to interest paid on cash held within non-cash ISAs.
- Nothing changes yet: the limit reduction takes effect in April 2027, not now.
What exactly is changing?
The annual ISA allowance is the total you can put into ISAs in a tax year. GOV.UK sets it at £20,000 for 2026 to 2027, and the ISA types include cash, stocks and shares, innovative finance and lifetime ISAs. Interest and gains inside an ISA are tax-free, and you must be 18 or over to open one.
Until now, a saver could put the whole £20,000 into a cash ISA if they wished. From 6 April 2027, the HM Revenue & Customs policy paper says, the annual cash ISA subscription limit for people under 65 will be reduced to £12,000, within the overall ISA subscription limit of £20,000. In practice, that means:
- A saver under 65 who wants to use the full allowance can put up to £12,000 into cash and the remaining £8,000 into other ISA types, such as stocks and shares.
- A saver under 65 who prefers cash can still save more than £12,000, but anything above the cash ISA limit would have to go into an ordinary savings account, where interest is not sheltered by the ISA.
- A saver aged 65 or over can continue to put up to £20,000 a year into a cash ISA.
The overall £20,000 allowance is unchanged. The government is not shrinking the total, only narrowing how much of it can be held in cash.
Why is the government doing this?
The government’s stated objective is clear. The policy paper says the measure is intended to encourage greater retail investment and improve long-term returns for savers. The June 2026 factsheet describes the same purpose, saying the rules protect a lower cash ISA limit so as to “encourage retail investment and supporting better returns for savers.”
That is a policy argument rather than a neutral fact, and savers are entitled to weigh it for themselves. The case in favour is that money held in stocks and shares has, over long periods, historically offered different returns from cash. The case for caution is that investments can fall as well as rise, and that many people use cash ISAs precisely because they want certainty and easy access. Neither point is settled by the government’s papers, and what is right for an individual depends on their goals, timeframe and tolerance for risk.
The anti-circumvention rules
Cutting a limit is easy. Stopping people from working around it is harder. The government’s factsheet, published on 23 June 2026, sets out rules intended to protect the lower limit. They matter because they close off the obvious workarounds.
No transfers from non-cash ISAs into cash ISAs. The factsheet says transfers from non-cash ISAs into cash ISAs “will not be permitted” for people under 65. The evident purpose is to stop a saver putting money into a stocks and shares ISA and then moving it into cash, which would leave them with more in cash than the new limit allows.
A 22% charge on cash held inside non-cash ISAs. The factsheet says a flat-rate 22% charge will apply to any interest or alternative finance return paid on cash held within a non-cash ISA. This appears aimed at people who might park cash inside a stocks and shares ISA to earn interest without using the cash ISA allowance.
Non-cash ISAs made up entirely of cash-like assets will not qualify. The factsheet says non-cash ISA portfolios composed of 100% cash-like assets will become non-qualifying investments. From April 2027, “cash-like assets” will be defined as money market funds only, and ISA managers will have to report the market value of those holdings.
Different treatment for over-65s. The factsheet says those aged 65 and over retain the £20,000 cash ISA limit, with modified restrictions. The detail of those modified restrictions is worth checking in the official papers if it applies to you.
Taken together, the rules signal that the government does not intend the £12,000 limit to be a soft one. They also add complexity: anyone with a mix of cash and investments in their ISAs should check how their provider will apply them.
What is still unclear?
Several practical questions are not answered by the documents reviewed for this article, and it is better to say so than to guess.
- When age is tested. The policy paper sets different limits for those under 65 and those aged 65 and over, but the summary does not spell out the point at which age is assessed. That matters for savers who turn 65 around the change.
- What happens to existing cash ISA balances. The paper does not describe any change to money already held in cash ISAs. It concerns new subscriptions from April 2027. Savers should confirm the position with their provider.
- How providers will implement the rules. ISA managers face new reporting duties, and customers may see changes to products and terms as April 2027 approaches.
None of this is a reason for panic. It is a reason to read the final guidance and provider communications carefully when they arrive.
How might the change affect different savers?
Because the policy changes only new subscriptions from a set date, its effect depends on how you save.
The regular saver who fills a cash ISA each year. Someone who currently puts a large share of their allowance into cash will need to decide what to do with the portion above £12,000 once the change takes effect: invest it in a stocks and shares ISA, hold it in an ordinary savings account, or use the portion differently. That is a personal decision, and nothing in the rules dictates the answer.
The cautious saver. Someone who wants to avoid investment risk is not forced to invest. They can keep saving in cash, but the ISA wrapper will shelter less of it from April 2027. Interest on savings held outside an ISA may be taxable depending on personal circumstances, so it is worth checking the tax position that applies to you.
The saver approaching 65. Whether the over-65 limit applies depends on how and when age is tested, which the summary papers do not make explicit. Anyone close to the threshold should check the final rules before relying on either limit.
The household using ISAs as an emergency fund. Cash ISAs are popular for money people want to be able to reach quickly. Our guide to how UK households manage cash explores why holding easily accessible money matters, and our explainer on what financial resilience means sets out why many people keep a buffer in cash even when they also invest. The policy does not stop anyone holding cash. It limits how much of it can sit inside the tax-free wrapper each year.
Cash or investments: what to weigh
The government’s aim is to nudge savers toward investing, so it is worth being clear about the trade-offs, without telling anyone what to do.
- Risk. Cash in a UK bank or building society account is a different proposition from shares or funds, whose value can fall. A stocks and shares ISA carries the risk that you get back less than you put in.
- Time horizon. Money you may need within a few years is usually treated differently from money you will not touch for a decade or more.
- Charges. Investment products carry charges that reduce returns. Our explainer on why investment fees matter shows how small percentages compound over time.
- Access. Cash is typically easy to reach. Investments may take longer to sell, and prices may be low when you need them.
- Tax. ISAs shelter interest and gains from tax, but the value of that shelter depends on your circumstances.
These are considerations, not recommendations. If you are unsure how to split your savings between cash and investments, a regulated financial adviser can help with your individual circumstances.
Frequently asked questions
When does the cash ISA limit change?
On 6 April 2027. Until then, the existing rules apply.
Does the overall ISA allowance fall?
No. The overall annual allowance stays at £20,000. Only the amount that can go into a cash ISA changes, for people under 65.
Who keeps the £20,000 cash ISA limit?
According to the government, people aged 65 and over retain a £20,000 cash ISA limit, with modified restrictions under the anti-circumvention rules.
Will I lose money I already hold in a cash ISA?
The documents reviewed for this article do not describe any change to balances already held. The limit applies to new subscriptions from April 2027. Check with your ISA provider for confirmation.
What is the 22% charge?
It is a flat-rate charge on interest or alternative finance returns paid on cash held within a non-cash ISA, designed to stop people holding cash inside stocks and shares ISAs to get around the cash ISA limit.
The bottom line
The cash ISA change is a deliberate nudge: the government wants more money to move from cash into investments, and it has built rules to make sure savers cannot easily avoid it. For anyone who relies on cash ISAs, the sensible response is not alarm but attention. The limit does not bite until April 2027, the overall allowance is unchanged, and several details, including how age is tested, are still worth checking in the final guidance. In the meantime, the fundamentals of saving have not changed: know what you are saving for, how soon you may need the money, and how much risk you can accept.
What this article is not
This is a report on published government policy, not personal financial advice or a recommendation to buy any product. Rules can change, and the treatment of your savings depends on your circumstances. Consider advice from a professional authorised to give regulated financial guidance in the UK.
Sources: GOV.UK — Cash Individual Savings Account (ISA) limit reduction, HM Revenue & Customs policy paper, published 17 September 2026; GOV.UK — ISA reform 2027: anti-circumvention rules factsheet, published 23 June 2026; GOV.UK — Individual Savings Accounts.
