From April 2027, the annual Cash ISA allowance for individuals under 65 will be cut to £12,000. This marks a substantial reduction from the current £20,000 overall ISA limit, a figure that has allowed savers considerable flexibility in where they place their tax-free funds.
This isn't merely a tweak; it's a clear signal from the Treasury, confirmed by HMRC, designed to reshape how Britons utilise their Individual Savings Accounts. While the overall ISA allowance will remain at £20,000, the specific allocation to cash will be capped for many, pushing them to consider other investment avenues.
What Changed and By How Much?
- **Cash ISA Allowance:** For those under 65, the maximum annual contribution to a Cash ISA will drop from the current £20,000 (as part of the overall allowance) to £12,000, effective from 6 April 2027.
- **Older Savers Exempt:** Individuals aged 65 and over will retain their ability to contribute up to £20,000 to Cash ISAs.
- **Other ISA Types:** The allowance for Stocks & Shares ISAs, Innovative Finance ISAs, and Lifetime ISAs (subject to its £4,000 sub-limit) will effectively remain at £20,000.
- **Tax on Cash in Stocks & Shares ISAs:** From April 2027, interest earned on uninvested cash held within a Stocks & Shares ISA will be subject to a flat-rate charge of 22%. This charge will be handled by ISA managers, not individuals, and is intended to discourage long-term cash holdings in accounts designed for investment.
- **Junior ISA (JISA):** The annual limit for Junior ISAs remains £9,000 for the 2026/27 tax year.
The government's stated aim, as articulated by the Treasury, is to encourage retail investment and support better returns for savers. This comes at a time when Cash ISAs have seen a resurgence in popularity, attracting £69.5 billion in subscriptions in the 2023/24 tax year alone. This represented more than 60% of all ISA subscriptions and contributed to a 20.1% increase in the total market value of ISA holdings, which reached £872 billion.
The Exchequer cost of ISA tax relief also rose to an estimated £9.4 billion in 2024/25, almost a fifth up on the previous year, partly driven by higher interest rates. The Bank of England's base rate currently sits at 3.75%, held on 18 June 2026, while UK inflation is at 2.8%.
Scenario: What This Means For You
If you are under 65 and primarily save cash:
Currently, you can put your full £20,000 annual ISA allowance into a Cash ISA. From April 2027, this will be restricted to £12,000. If you wish to save more than this tax-free, you will need to consider a Stocks & Shares ISA or an Innovative Finance ISA for the remaining £8,000 of your overall allowance.
If you hold significant uninvested cash in a Stocks & Shares ISA:
From April 2027, any interest earned on that cash will incur a 22% flat-rate charge. This is a clear directive to either invest the cash or move it to a dedicated Cash ISA, where it would be tax-free up to your allowance.
If you are a first-time buyer:
The Treasury has promised a new first-time buyer ISA with no upper age limit, reflecting the rising average age of first-time home purchases. This new ISA will still offer a government bonus of 25% of the sum saved, paid when a property is bought, and crucially, will remove the 25% penalty for withdrawals for other reasons. This is a significant improvement on the current Lifetime ISA (LISA) rules, which cap contributions at £4,000 per year and impose a penalty for non-house purchase withdrawals.
But There Are Risks
While the Treasury frames these changes as encouraging investment, the reduction in the Cash ISA allowance for younger savers could be seen as penalising those who prefer the security of cash, particularly in uncertain economic times. For individuals with lower risk appetites, being nudged towards market-based investments may not align with their financial goals or understanding. The average savings in the UK are £19,214, but this is skewed, with many having far less, and 39% having £1,000 or less.
What this means for you
It is prudent to review your current savings strategy, particularly if you are under 65 and rely heavily on Cash ISAs. Consider whether a Stocks & Shares ISA aligns with your long-term goals for any funds exceeding the new £12,000 Cash ISA limit. For those holding uninvested cash within a Stocks & Shares ISA, plan to either invest these funds or transfer them to a Cash ISA before April 2027 to avoid the new 22% charge. First-time buyers should monitor developments on the promised new ISA, which appears to offer more flexibility than existing options. Always remember that interest earned on standard savings accounts may be subject to tax above your Personal Savings Allowance (£1,000 for basic rate taxpayers, £500 for higher rate), making ISA alternatives a crucial consideration for larger sums.
When Effective
The changes to the Cash ISA allowance and the tax on cash in Stocks & Shares ISAs will take effect from 6 April 2027. The new first-time buyer ISA is a Treasury promise, and further details on its implementation date are awaited.
Where to Get Help
For personalised advice on how these changes might affect your specific financial situation, consider seeking guidance from an independent financial adviser.
This is not financial advice. Seek independent financial guidance. Interest on standard accounts may be subject to tax above your Personal Savings Allowance.
Sources
- HM Revenue & Customs (HMRC) — Confirmation of ISA reforms (June 2026)
- Treasury — Autumn Budget 2025 announcements on ISA policy
- Treasury — Statement on new first-time buyer ISA (June 2026)
- Bank of England — Monetary Policy Committee decision (18 June 2026)
- Office for National Statistics (ONS) — UK inflation rate, household saving ratio, average UK savings (2026)