By James Whitfield | UK Life
From 6 April 2027, anyone under 65 will only be able to put £12,000 a year into a Cash ISA, down from £20,000 now. The overall £20,000 ISA allowance stays the same — the remaining £8,000 has to go into a Stocks and Shares ISA, an Innovative Finance ISA, or a Lifetime ISA instead. Chancellor Rachel Reeves confirmed the cap at the Autumn Budget on 26 November 2025, and HMRC published the detailed rulebook on 23 June 2026.
If you’re under 65 and rely on cash savings, it’s worth understanding this properly — not just the lower cap, but also a set of anti-avoidance rules that most coverage hasn’t addressed.
Quick Facts: Cash ISA Changes at a Glance
- New Cash ISA limit (under 65): £12,000 a year, from 6 April 2027
- Overall ISA allowance: stays at £20,000 — unchanged
- Cash ISA limit (65+): stays at £20,000, from the start of the tax year you turn 65
- This tax year (2026/27): no change — full £20,000 can still go into cash
- New 22% charge: on interest earned on cash left inside a Stocks & Shares or Innovative Finance ISA, from April 2027
- Transfers banned: Stocks & Shares/Innovative Finance ISA into Cash ISA, for under-65s, from April 2027
- Announced: Autumn Budget 2025, 26 November 2025, by Chancellor Rachel Reeves
- Confirmed in detail: HMRC factsheet, 23 June 2026
What’s Changing to the Cash ISA £12,000 Cap From April 2027?
From 6 April 2027, savers under 65 can put a maximum of £12,000 into a Cash ISA each tax year, according to HM Revenue & Customs. The overall £20,000 allowance doesn’t shrink — it just has to be split differently, with at least £8,000 going into an investment-type ISA to use the whole thing. Nothing changes for the current 2026/27 tax year: the full £20,000 can still go entirely into cash right up until 5 April 2027.
Existing Cash ISA balances built up before the change are unaffected. Money already in a Cash ISA keeps its tax-free status — the £12,000 limit only applies to new contributions from 6 April 2027 onward.
Why Is the Cash ISA Allowance Being Cut?
The Treasury wants to shift some of the roughly £360 billion sitting in UK cash ISAs into stocks and shares, arguing cash savers have missed out on stronger long-term returns. A Treasury Select Committee report found that households hold that much in cash ISAs, while subscriptions to stocks and shares ISAs fell by 9% between 2021–22 and 2023–24, even as cash ISA contributions more than doubled. IG’s analysis of HMRC figures adds two more data points: cash ISA savers earned roughly one-seventh the real returns of UK equity investors over 26 years, and 700,000 more cash ISA accounts opened in 2022–23, while stocks and shares ISA numbers fell by 126,000.
It wasn’t a straightforward decision. Reeves had reportedly considered a stricter £10,000 cap before settling on £12,000, per Financial Times reporting picked up by the Independent. The Building Societies Association warned £10,000 could cost enough deposit funding for around 60,000 fewer mortgages a year, and MoneySavingExpert founder Martin Lewis pushed for over-65s to be shielded — a carve-out the Chancellor built in.
The New Anti-Circumvention Rules Explained
On 23 June 2026, HMRC published a factsheet on stopping people from working around the £12,000 cap — the part that most coverage hasn’t addressed yet. Three measures stand out.
A 22% charge on cash left in non-Cash ISAs. From April 2027, interest or returns paid on cash sitting inside a Stocks & Shares ISA or Innovative Finance ISA face a flat 22% charge, collected by the ISA manager and paid to HMRC — designed to stop people parking cash in an investment wrapper purely to dodge the £12,000 limit.
No more all-cash “investment” ISAs. A Stocks & Shares ISA made entirely of Money Market Funds — low-risk funds that behave like cash — counts as a non-qualifying investment from April 2027. Diversified portfolios with some money market exposure remain fine.
Transfers into Cash ISAs are restricted. Under-65s won’t be able to transfer money from a Stocks & Shares ISA or an Innovative Finance ISA into a Cash ISA; transfers in the other direction are allowed.
Savers turning 65 get most of this relaxed: from the start of that tax year, the transfer restriction drops away, and the full £20,000 cash allowance applies, though the 22% charge on cash held elsewhere still applies at any age. A technical consultation on the draft legislation is due before regulations are laid in autumn 2026, ahead of the 6 April 2027 start date.
Cash ISA Rules: Now vs From April 2027
| Rule | Now (2026/27) | From 6 April 2027 |
|---|---|---|
| Cash ISA limit, under 65 | £20,000 | £12,000 |
| Overall ISA allowance | £20,000 | £20,000 (unchanged) |
| Cash ISA limit, 65 and over | £20,000 | £20,000 (unchanged) |
| Transfers, non-Cash ISA → Cash ISA | Allowed | Banned for under-65s |
| Interest on cash held in a non-Cash ISA | Tax-free | 22% charge |
| 100%-cash-like Stocks & Shares ISA | Allowed | Non-qualifying investment |
| Tax on savings interest outside an ISA | Current rates | Up 2 percentage points, all bands |
Source: HM Revenue & Customs, “ISA reform 2027: anti-circumvention rules factsheet,” published 23 June 2026.
Who Is Affected — and Who Isn’t?
Anyone under 65 who fills, or plans to fill, their whole £20,000 ISA allowance with cash is affected. £8,000 of it will need to go into a Stocks & Shares ISA, Innovative Finance ISA, or Lifetime ISA from April 2027 to use it all, or you save less overall.
If you’re 65 or over, none of this touches, you keep the full £20,000 Cash ISA allowance from the start of the tax year you turn 65, not your actual birthday.
The wider tax backdrop is tightening too. Reeves confirmed savings and dividend tax rates outside an ISA will rise two percentage points across all bands from April 2027. HMRC data obtained by AJ Bell via a Freedom of Information request shows 2.64 million people are expected to pay tax on savings interest in 2025/26, up from 647,000 in 2021/22, a sign of how much more the ISA wrapper now matters. For more on organising day-to-day finances alongside your ISA planning, see our guide to cash management solutions in the UK.
What’s Happening to the Lifetime ISA?
The Lifetime ISA isn’t being scrapped immediately, but its replacement is taking shape. On 23 June 2026 — the same day as the anti-circumvention rules the government launched a consultation on a new First Time Buyer ISA to replace the LISA, with cash and investment versions and no exit penalty for savers who don’t buy a home. That consultation closes 17 August 2026.
Existing LISAs aren’t affected, meanwhile. You can keep contributing, and new ones can still be opened, until the replacement launches reportedly around April 2028, though the Treasury hasn’t confirmed a date.
How to Prepare Before April 2027
You’ve got the rest of the 2026/27 tax year to use the current £20,000 cash allowance if that suits you. A few practical steps:
- Use this year’s full allowance if cash suits you. For 2026/27, the whole £20,000 can still go into a Cash ISA — this doesn’t apply if you’ll turn 65 before 6 April 2027, since the cut never touches you.
- Plan where the “extra” £8,000 will go. From April 2027, decide whether that portion sits in a Stocks & Shares ISA, Innovative Finance ISA, or Lifetime ISA, rather than defaulting to cash you can no longer put there.
- Don’t try to park cash inside a Stocks & Shares ISA. The 22% charge and the ban on 100%-cash-like portfolios exist specifically to close that route.
- Keep an eye on the wider picture. Trimming fixed costs elsewhere can free up room to save — see our guide on cutting UK energy bills by £300 a year. It’s also worth checking your credit score for free before any big savings or borrowing decisions.
None of this is financial advice — for a decision specific to your circumstances, a regulated financial adviser or Citizens Advice can help.
FAQ: Cash ISA £12,000 Cap 2027
When does the £12,000 Cash ISA limit start?
From 6 April 2027, for Cash ISA contributions made by savers under 65.
Will my existing Cash ISA savings be affected?
No. Money saved before 6 April 2027 retains its tax-free status; the £12,000 cap applies only to new contributions from that date.
Does the cap apply to everyone?
No. Savers who are 65 or over from the start of the relevant tax year keep the full £20,000 Cash ISA allowance and aren’t subject to the new transfer restrictions.
Can I still move money from a Stocks & Shares ISA into a Cash ISA?
Not if you’re under 65. From April 2027, that transfer direction is banned for under-65s, though transfers the other way remain allowed.
Is the Lifetime ISA being scrapped?
Not immediately. It will eventually be replaced by a new First Time Buyer ISA, under consultation until 17 August 2026, but existing LISAs can still be opened and funded until the replacement launches.
The £12,000 cap on Cash ISAs is confirmed government policy, not speculation. It takes effect on 6 April 2027 with real anti-avoidance rules attached. Nothing forces you to act before then, but working out where your remaining £8,000 will go now makes the transition far less stressful than leaving it to the last week of the tax year.
Small Business & Productivity Writer
James Whitfield writes about the tools, software, and automation that help UK freelancers and small businesses work smarter. He tests apps hands-on and breaks down what actually works, without the jargon.