How the Cash ISA Cap Will Push Savers to Invest 

At the Autumn Budget 2025, Chancellor Rachel Reeves confirmed major updates to the tax-free savings system that will change how millions of UK savers use their ISA allowance. The reforms mean that keeping large sums in cash will become less tax-efficient for many people under 65. Here’s what’s changing and how to prepare before the deadline.

New Cash Restrictions From April 2027

From 6 April 2027, the maximum amount that under-65s can pay into a cash ISA will drop from £20,000 to £12,000 per tax year. The overall ISA limit will stay at £20,000, which means the remaining £8,000 must go into other types of ISAs, such as stocks and shares ISAs. People aged 65 and over are exempt and can continue paying their full allowance into cash if they wish, with the exemption applying from the start of the tax year in which they turn 65.

The government’s aim is to nudge savers towards equities and retail investments for better long-term returns. It’s a meaningful shift in a country where, according to HMRC, around £360 billion sat in cash ISAs at the end of the 2023/24 tax year.

What This Means for Cash Savers

The reform will have a real impact on UK adults holding sizeable cash balances. According to the FCA’s Financial Lives Survey 2024, 61% of adults with £10,000 or more in investible assets hold at least three quarters of that money in cash rather than investments, up from 58% in 2022. These savers will face limits on how much new money they can shield from tax inside a cash wrapper each year.

Moving money into stocks and shares means dealing with market fluctuations, which can feel unfamiliar to anyone used to the steadiness of cash. For savers weighing up that shift on larger sums, professional investment management services offer a structured alternative to picking funds on your own, with portfolios built around your goals, risk appetite and timeline.

Strict Rules on Transfers and Cash Inside Investment ISAs

To stop savers working around the new cap, the government is bringing in anti-circumvention rules. From 6 April 2027, under-65s won’t be able to transfer money from a stocks and

shares ISA or innovative finance ISA into a cash ISA at all, though transfers in the other direction will still be allowed.

Cash held inside a non-cash ISA will face a flat 22% charge on any interest earned, regardless of your age or tax band. Money market funds will be the only cash-like asset permitted inside an investment ISA, and they can’t make up 100% of the account.

It’s worth noting that this 22% charge applies to everyone, including savers over 65. The age exemption only covers the cash ISA contribution limit, not cash held inside investment ISAs.

Existing cash ISA balances are protected. Any money you’ve already saved before April 2027 will remain tax-free and won’t be affected by the new rules. The restrictions apply only to new contributions made after the deadline.

Other Ways to Use Your £20,000 Allowance

If you’re under 65 and want to make the most of your tax-free allowance, you’ll need to think about where the remaining £8,000 goes. You can split this across different accounts depending on your situation and your appetite for risk.

The main tax-free options under the ISA umbrella:

• Stocks and shares ISAs, which let you invest in equities, bonds, and funds.
• Innovative finance ISAs, which focus on peer-to-peer lending matching borrowers with investors. These will also be subject to the 22% charge on cash interest.
• Lifetime ISAs, which currently pay a 25% government bonus on up to £4,000 a year for first-time buyers or retirement savers. The government has launched a consultation on replacing the LISA with a new First-Time Buyer ISA, which would remove the withdrawal penalty. The consultation closes in August 2026, so the final details aren’t settled just yet.

Each option carries distinct rules and risks. Cash deposits are protected by the Financial Services Compensation Scheme up to £120,000 per person, per banking licence.

Strategy Reviews Before the Deadline

Savers still have time to plan before the new caps come in. Making the most of your current £20,000 cash ISA allowance in the 2026/27 tax year is an easy way to protect as much cash as possible under the old rules. It also gives you a clear window to review your longer-term strategy.

Rather than waiting until the final weeks, look at your portfolio now and work out how much risk you’re comfortable taking. Shifting from cash to investments takes time and careful thought, and starting early means you won’t be making rushed decisions when the rules change.

The value of your investments and the income from them may go down as well as up, and you could get back less than you invested. Past performance shouldn’t be seen as an indication of future performance.