The government has confirmed further detail on its planned ISA reforms, and while the measures are being presented as part of a wider package of tax simplification, modernisation and fairness, the practical impact for many savers may feel anything but simple.
From 6 April 2027, the annual Cash ISA limit for savers under 65 will reduce to £12,000, while the overall ISA allowance will remain at £20,000. Those aged 65 and over will continue to be able to place the full £20,000 into a Cash ISA.
The direction of travel is clear: the government wants more people to consider investing, rather than holding all of their ISA savings in cash.
However, the latest update goes further than simply lowering the Cash ISA limit. To stop savers from working around the new rules by placing cash into a Stocks and Shares ISA or Innovative Finance ISA, the government has confirmed a set of anti-circumvention measures that will apply from April 2027.
The most eye-catching measure is a 22% charge on interest paid on cash held within non-Cash ISAs, including Stocks and Shares ISAs and Innovative Finance ISAs. In other words, where cash is left sitting inside an investment ISA and earns interest, that interest will no longer be entirely protected in the way many savers have come to expect from an ISA wrapper.
That is a significant change in principle. ISAs have long been understood as tax-free products, allowing interest, dividends and gains to be sheltered from tax. Introducing a charge within that environment creates a new layer of complexity, particularly for individuals who may have only modest investment balances or who hold cash temporarily while deciding what to buy, waiting for market conditions to settle, or covering platform fees.
The government has also said that transfers from non-Cash ISAs into Cash ISAs will not be permitted for under-65s. Transfers in the other direction, from Cash ISAs into Stocks and Shares ISAs or Innovative Finance ISAs, will still be allowed. This supports the policy aim of encouraging investment, but it could reduce flexibility for savers who later decide they want to move back into cash.
There will also be restrictions on holding cash-like assets. HMRC has indicated that Money Market Funds will be treated as cash-like for this purpose, and that a non-Cash ISA will not be able to consist entirely of such assets. The intention is to prevent savers from using low-risk, cash-style investments as a substitute for a Cash ISA, while still allowing some flexibility for normal investment activity.
The policy rationale is understandable. More people currently use Cash ISAs than Stocks and Shares ISAs, and cash savings may deliver lower long-term returns than investments. Encouraging greater participation in investment markets could, in theory, improve outcomes for some savers and support wider economic growth.
However, the practical reality is more complicated. Not every saver is ready, willing or able to invest. Some may need access to cash in the short term. Others may be cautious because of market volatility, personal circumstances or simply because the amounts involved are relatively small. For those individuals, the new rules may feel less like encouragement and more like pressure, or even punitive.
There is also an administrative challenge. Taxpayers, advisers and ISA providers have been used to treating ISA income as something that can largely be ignored for tax reporting purposes. A new charge on cash interest within certain ISAs introduces more moving parts, more communication with savers, and more scope for misunderstanding.
Savers should also consider the wider tax position. Although further operational detail is expected, interest charged within an ISA could still be relevant when looking at broader personal tax outcomes, particularly where income levels affect matters such as the High Income Child Benefit Charge, tax-free childcare entitlement or the tapering of the personal allowance.
For now, the key message is not to panic, but to plan. The changes are not due to take effect until April 2027, which gives savers time to review how they use their ISA allowance, whether they are likely to be affected by the reduced Cash ISA limit, and whether holding cash within an investment ISA will still make sense for them.
The right answer will depend on individual circumstances, including age, risk appetite, savings goals, investment horizon and the need for ready access to funds. For some, investing more of their ISA allowance may be appropriate. For others, the security and accessibility of cash will remain the priority, even with a lower annual limit.
If you are unsure how the ISA changes could affect your savings, investments or wider tax position, Hillier Hopkins can help you review your options and plan ahead with confidence. Please get in touch with your usual Hillier Hopkins adviser for tailored guidance.
