Introduction
For advisers, the key task is to understand how the current regime compares with the incoming rules, which clients are most likely to be affected, and where planning conversations may be needed before the changes take effect.
Key changes at a glance
- The overall adult ISA subscription limit remains £20,000 and is expected to stay frozen until April 2031
- From 6 April 2027, the annual Cash ISA subscription limit will reduce to £12,000 for individuals under 65
- Individuals aged 65 and over will retain a £20,000 Cash ISA limit, with entitlement applying from the start of the tax year in which they turn 65
- Anti-circumvention rules will prevent clients from simply using Stocks and Shares ISAs or Innovative Finance ISAs as substitute Cash ISAs
- A 22% charge will apply to interest, or alternative finance returns, paid on cash held within non-Cash ISAs
- Transfers from non-Cash ISAs into Cash ISAs will be restricted for under-65s, while Cash ISA to non-Cash ISA transfers will remain possible
- Mandatory digital ISA reporting has been deferred until April 2028, one year after the Cash ISA reforms are due to begin
- Junior ISA and Child Trust Fund limits remain £9,000, and the Lifetime ISA limit remains £4,000
Current ISA regime (Pre April 2027)
Under the current regime, adult investors can subscribe up to £20,000 per tax year across permitted ISA types. The allowance can be split between Cash ISAs, Stocks and Shares ISAs, Innovative Finance ISAs and Lifetime ISAs. Income and capital gains within an ISA are free from income tax, dividend tax and capital gains tax.
What is changing from 6 April 2027?
The core policy change is a reduction in the amount that some clients can subscribe to Cash ISAs each tax year. The overall adult ISA allowance remains £20,000, but from 6 April 2027 clients under the age of 65 will only be able to use up to £12,000 of that allowance for Cash ISA subscriptions. The remaining allowance can still be used for non-Cash ISA subscriptions, such as Stocks and Shares ISAs or Innovative Finance ISAs.
Client group | Cash ISA limit from 6 April 2027 | Planning point |
|---|---|---|
Under 65 | £12,000 | Review clients using Cash ISAs for more than £12,000 a year and consider whether surplus cash is short-term cash, taxable savings, or suitable for investment |
65 and over | £20,000 | The full Cash ISA limit applies from the start of the tax year in which the client turns 65 |
New anti-circumvention rules
The government intends to prevent clients from working around the lower Cash ISA limit by holding cash, or cash-like assets, inside non-Cash ISA wrappers. The rules are intended to preserve normal investment flexibility while discouraging long-term tax-free cash holdings inside investment ISAs.
- Charge on interest paid on cash in non-Cash ISAs
From 6 April 2027, a flat-rate 22% charge will apply to interest, or alternative finance returns, paid on cash held inside non-Cash ISAs. This includes cash held within Stocks and Shares ISAs and Innovative Finance ISAs. The charge will be paid by ISA managers to HMRC; clients will not need to report ISA interest to HMRC personally. The Personal Savings Allowance (PSA) does not apply to ISA interest.
For advisers, the practical point is that cash can still be held within investment ISAs where needed for platform operations, liquidity or phased investment. However, clients should not assume that uninvested cash in a non-Cash ISA will continue to receive fully tax-free interest after the reforms begin.
- Non-Cash ISA portfolios made up of 100% cash-like assets will be non-qualifying investments
For this measure, the government’s current definition of “cash-like assets” is deliberately narrow.
From April 2027, cash-like assets are expected to mean Money Market Funds only. These holdings can still sit within a non-Cash ISA where they form part of a wider investment portfolio, but a non-Cash ISA account invested entirely in cash-like assets will become non-qualifying.
A Money Market Fund is broadly a low-risk, highly liquid fund that invests in short-term debt securities.
No specific percentage threshold or tolerance has been indicated beyond the statement that the restriction applies where cash-like assets make up 100% of the investments in the account.
Common investment holdings such as shares, funds, investment trusts, exchange-traded funds, corporate bonds, government bonds and UK gilts are not expected to be treated as cash-like assets under this measure. This distinction matters where advisers use money market exposure for liquidity management or short-term parking within a broader portfolio.
- Restrictions on transfers into Cash ISAs
From 6 April 2027, transfers from non-Cash ISAs into Cash ISAs will not be permitted for clients under 65. This is designed to prevent clients from subscribing the full £20,000 into a non-Cash ISA and then transferring the funds back into a Cash ISA to recreate a larger cash shelter.
Cash ISA to Cash ISA transfers and Cash ISA to non-Cash ISA transfers are expected to remain possible. For clients aged 65 and over, the transfer restriction will be disapplied from the start of the tax year in which they turn 65.
Other ISA changes and related developments
- Allowance freeze to April 2031
The adult ISA limit is expected to remain at £20,000 until April 2031. Junior ISA and Child Trust Fund limits remain at £9,000, and the Lifetime ISA limit remains at £4,000. The freeze increases the importance of wrapper prioritisation where clients have surplus savings and investments outside tax-efficient structures.
- Lifetime ISA and proposed first-time buyer product
The government has indicated that it will consult on a new first-time buyer-only product. The aim is to provide the bonus when a saver buys a first home, while removing the need for a withdrawal charge and giving savers more flexibility if their circumstances change. It remains possible to open a Lifetime ISA until any new product becomes available, and existing Lifetime ISA holders will be able to continue saving under current rules indefinitely.
- Digital ISA reporting delayed to April 2028
Mandatory digital ISA reporting has been postponed until April 2028. This means the Cash ISA reforms are expected to proceed from April 2027 using existing reporting methods, with digital reporting mandation following one year later.
Client planning implications
The reforms do not remove ISAs and do not reduce the overall adult ISA allowance. The main planning impact is more targeted: clients under 65 will have less scope to shelter cash within a Cash ISA, while the government is also limiting the ability to use non-Cash ISAs as long-term cash substitutes.
For clients with larger cash reserves, the conversation is likely to shift from “how much can be put into a Cash ISA?” to “what is the cash for?” Money needed for emergency funds, short-term spending or known liabilities may still justify remaining in cash, even if some of it sits outside the ISA wrapper. Longer-term surplus cash may need to be considered alongside investment risk, time horizon, tax position and wider wrapper availability.
Clients approaching age 65 may require more careful timing. The higher Cash ISA limit is expected to apply from the start of the tax year in which the client turns 65, so the effect of the reforms may differ depending on the client’s age, tax year position and intended subscription pattern.
- Clients holding cash in investment ISAs – the issue is not whether cash can ever be held, but whether clients understand that interest on cash held in non-Cash ISAs will be subject to the 22% charge from April 2027
- Clients using money market funds – these holdings may remain appropriate as part of broader portfolio management, but advisers should be alert to accounts that could be viewed as wholly cash-like
- Clients considering transfers – under-65s may lose the ability to move funds from non-Cash ISAs into Cash ISAs after the rules take effect, so any intended transfers should be considered in advance
- First-time buyers – Lifetime ISA planning should remain under review while the proposed first-time buyer product develops, particularly where flexibility, withdrawal penalties and purchase timing are relevant
Adviser checklist
- Segment clients under 65 who regularly use Cash ISA subscriptions above £12,000
- Flag non-Cash ISA accounts with high cash or money market fund exposure
- Review planned non-Cash ISA to Cash ISA transfers before 6 April 2027
- Update review meeting prompts and annual allowance scripts
- Check client communications distinguish the £20,000 overall ISA allowance from the new Cash ISA sub-limit
- Monitor final legislation, HMRC guidance and provider implementation updates
Adviser client conversations
“The ISA allowance is not disappearing, and the overall adult ISA limit remains £20,000. What is changing from April 2027 is the amount most people can put into a Cash ISA each year.
If you are under 65, the Cash ISA limit will reduce to £12,000, while the rest of the allowance can still be used in other ISA types.
The government is also introducing rules to stop investment ISAs being used simply as cash accounts, so we should review how your ISA allowance, cash holdings and investment time horizons fit together before the new rules start.
Summary
The April 2027 reforms do not reduce the overall adult ISA allowance, but they materially change how cash can be held within the ISA regime for clients under age 65. Advisers should identify affected clients early, review cash and transfer strategies, assess the ongoing suitability of cash holdings and ensure client communications clearly distinguish between the unchanged overall ISA allowance and the new Cash ISA sub-limit.
Implementation timetable
Change or milestone | Adviser action | |
|---|---|---|
2026/27 tax year | Current ISA rules continue to apply | Clients can still use the current £20,000 adult ISA allowance, including Cash ISA subscriptions within the overall limit |
Autumn 2026 | HMRC expects to continue industry engagement and preparation for digital ISA reporting | Monitor provider communications and platform readiness |
Before April 2027 | Draft legislation and regulations are expected to be laid ahead of commencement | Review final rules once published and update client communications |
6 April 2027 | Cash ISA limit falls to £12,000 for under-65s. Overall ISA limit remains £20,000. Anti-circumvention rules begin | Review affected clients’ cash balances, ISA funding plans and transfer intentions before the start date |
April 2028 | Mandatory digital ISA reporting is expected to begin | Check operational implications for reporting, client data and provider processes |
April 2031 | Current freeze period for ISA, Junior ISA, Child Trust Fund and Lifetime ISA limits is expected to end | Reassess allowance planning once future policy is confirmed |
Additional reading
- HMRC, “ISA reform 2027: anti-circumvention rules factsheet”
- HMRC, “Tax-free savings newsletter 19 — November 2025”
- GOV.UK, “Individual Savings Accounts (ISAs): Overview”
- HM Treasury, “First Time Buyer ISA consultation”
- The Individual Savings Account (Amendment) Regulations 2025
