Cash ISA Allowance Cut to £12,000 From April 2027: How Under-65s, Over-65s and Stocks and Shares Savers Are Affected

The Chancellor confirmed at the Autumn Budget on 26 November 2025 that the annual Cash ISA subscription limit will be reduced from £20,000 to £12,000 for savers aged under 65, from 6 April 2027. Savers aged 65 and over will continue to use the full £20,000 in cash. The overall ISA allowance stays at £20,000 across all types. The remaining £8,000 for under-65s will need to be placed into a stocks and shares ISA, an Innovative Finance ISA, or (subject to its own £4,000 sub-limit) a Lifetime ISA.

What the rule actually does

Under current rules, an adult can pay up to £20,000 a year into any combination of cash, stocks and shares, Innovative Finance and Lifetime ISAs, with interest, dividends and capital gains earned inside the wrapper free of UK tax. From April 2027 the £20,000 ceiling stays, but for under-65s the cash subscription limit drops to £12,000. The £8,000 difference must go into investment-type wrappers if the saver wants to use the full annual allowance.

Why the age threshold

The policy is set out in HM Treasury's response to the Treasury Committee published on 14 January 2026, signed by Lucy Rigby MP, Economic Secretary to the Treasury. The stated aim is to encourage more household savings to flow into UK-listed companies. The Chair of the Treasury Committee, Dame Meg Hillier, has criticised the design as risking confusion for consumers. Older savers tend to rely more on cash income in retirement, which the Government cites as the basis for the over-65 exemption.

The 1p loophole in stocks and shares ISAs

Press coverage in late May 2026 highlighted that holding cash within a stocks and shares ISA will attract a 22 percent charge on interest from April 2027 under accompanying rules. However, the charge applies only where 100 percent of the investable assets in the wrapper are cash-like. In theory a saver could hold £7,999.99 in cash inside a stocks and shares ISA, place 1 pence in equities, and avoid the charge. HMRC had previously confirmed the principle but had not formally set the rate until recent guidance.

What savers can do before April 2027

The 2026/27 tax year, which began on 6 April 2026 and ends on 5 April 2027, is the last full year under the existing £20,000 cash rule for under-65s. Cash ISA take-up has historically risen ahead of confirmed allowance changes. Money already inside a Cash ISA before April 2027 is unaffected: interest stays tax-free and the balance can stay in cash indefinitely. The new rule applies only to new subscriptions from April 2027 onwards.

What about the Lifetime ISA and Junior ISA

The Lifetime ISA £4,000 sub-limit is unchanged until at least 5 April 2031. The Junior ISA and Child Trust Fund annual subscription limit of £9,000 is also unchanged. The Government has said it will consult on a new ISA product aimed at first-time property buyers, intended in time to replace the Lifetime ISA.

FAQs

Does the £12,000 limit apply to money already in my Cash ISA?

No. The new limit applies only to new subscriptions from 6 April 2027. Balances already in a Cash ISA remain fully tax-free and unaffected.

What if I turn 65 during a tax year?

Rules for savers who reach 65 partway through a tax year will be determined in 2026 following an industry consultation, according to HMRC.

Can I still split my allowance across multiple Cash ISAs?

Yes. From the 2025/26 tax year, savers can open and pay into multiple Cash ISAs in the same tax year, subject to the overall annual limit.

How much extra tax will be paid on savings interest outside ISAs?

From April 2027, tax rates on savings interest rise by 2 percentage points. Basic-rate savers will pay 22 percent (from 20 percent), higher-rate 42 percent (from 40 percent), and additional-rate 47 percent (from 45 percent).

23 June 2026: HMRC Confirms the Full Anti-Circumvention Rules

On 23 June 2026 HMRC published the anti-circumvention rules factsheet that confirms precisely how the 22% charge on cash in non-cash ISAs will operate from 6 April 2027. The factsheet, titled "ISA reform 2027: anti-circumvention rules factsheet", was published alongside the government's Tax Update 2026 package and fills in the implementation detail that was absent from the Autumn Budget 2025 announcement.

The charge is flat-rate at 22% and applies to all interest earned on cash held in stocks and shares ISAs and Innovative Finance ISAs. It is universal: it applies regardless of the account holder's age, income tax band, or whether they are a non-taxpayer. This last point is significant - a basic-rate taxpayer already faces a 20% charge on savings interest above their Personal Savings Allowance outside an ISA, but the 22% charge inside the wrapper removes the tax advantage of holding cash in a non-cash ISA entirely, and imposes a small extra levy. Even non-taxpayers, who currently pay no tax on savings interest, will be subject to the 22% charge on cash held inside stocks and shares or Innovative Finance ISAs from April 2027.

Sharia-Compliant Returns Caught; Money Market Funds Spared

Two clarifications in the 23 June factsheet carry practical implications for specific saver groups. First, the 22% charge explicitly covers "alternative finance returns" - the returns generated by Sharia-compliant ISA products that do not pay conventional interest but instead generate returns through profit-sharing or other structures. Muslim savers using Sharia-compliant investment accounts should note this extension of the charge beyond conventional interest.

Second, and of greater significance to the broader investment community, Money Market Funds (MMFs) held inside non-cash ISAs will not be classified as cash under the new rules, and therefore will not trigger the 22% charge - provided they do not make up 100% of the non-cash ISA holdings. HMRC's factsheet states that "cash-like assets will be eligible for non-cash ISAs, provided that they are partial allocations and do not make up 100% of the investments in an individual's non-cash ISA account." From April 2027, cash-like assets eligible under this rule are defined specifically as money market funds only.

The practical implication: a saver who holds, for example, 90% of their stocks and shares ISA in equities and 10% in a money market fund will not pay the 22% charge on any returns from that MMF position. However, a saver who moves their entire stocks and shares ISA into a money market fund to replicate cash ISA returns will find that holding reclassified as non-qualifying, and any interest or returns subject to the charge. HMRC has signalled that ISA managers will be required to report MMF market values via the end-of-year statistical return from 2027.

The Transfer Ban for Under-65s

A third anti-circumvention measure confirmed on 23 June is the transfer restriction for under-65 savers. From 6 April 2027, savers aged under 65 will not be permitted to transfer funds from a non-cash ISA (stocks and shares or Innovative Finance) into a cash ISA. Transfers in the other direction - from cash ISA into investment accounts - remain permitted.

The practical effect of this restriction is to prevent savers from accumulating funds inside a stocks and shares ISA wrapper (where the cash ISA limit does not apply) and then moving large lump sums back into a cash ISA to earn tax-free interest. Industry bodies have criticised the measure as reducing ISA flexibility at a time when many savers need to access lower-risk cash holdings as they approach retirement or face major expenditure. Savers aged 65 and over are not subject to the transfer ban and retain the full £20,000 cash ISA allowance.

HMRC has confirmed that regulations implementing all three anti-circumvention measures will be laid before Parliament in Autumn 2026, with the rules taking effect from 6 April 2027. The current 2026/27 tax year is unaffected: all savers can still use their full £20,000 allowance in any combination of ISA types, and transfers between ISA types remain unrestricted.

Industry Reaction to the 23 June Rules

The publication of the 23 June factsheet drew an immediate and largely critical response from investment platforms and savings industry bodies. Rachel Vahey, head of public policy at AJ Bell, said the reforms "reduce flexibility, entrench the divide between cash and investment accounts and introduce tax charges and complex age-related allowances." Vahey added that faced with increasingly complex ISA rules, many would-be investors would stick with what they know rather than take their first step into investing.

Katie Horne, savings expert at Flagstone, argued that the restrictions stop investors from making decisions that best suit their own needs. Interactive Investor noted that platforms are already warning that the administrative burden of calculating and withholding the 22% charge on cash inside wrappers could force some to eliminate the interest they pass on to consumers entirely.

Not all responses were negative. Tom Riley, Nationwide's Group Director of Retail Products, welcomed the clarification, stating that "ensuring a level playing field between cash and non-cash ISAs is vital to maintaining a sustainable savings ecosystem." The government's stated aim is to shift household savings flows toward UK-listed companies and generate better long-term returns for savers by steering them away from cash and into equity investment.