Cash ISA Allowance Rules for 2026/27 and 2027/28
The Cash ISA rules are changing. For the current 2026/27 tax year, the overall ISA subscription limit is still £20,000. From 6 April 2027, under-65s will face a separate £12,000 annual Cash ISA subscription limit while the overall ISA limit remains £20,000.
The current 2026/27 rule is still £20,000 overall
GOV.UK says the maximum you can subscribe across ISAs in the 2026/27 tax year is £20,000. There is not yet a separate lower Cash ISA subscription cap for this tax year. You can allocate the allowance between eligible ISA types subject to their own rules.
If you place the whole £20,000 into a Cash ISA during 2026/27, you have used the full overall ISA subscription allowance for that tax year. If you put £12,000 into cash, the remaining £8,000 can potentially be used in another ISA type, subject to that product's eligibility rules.
The tax year ends on 5 April 2027. Unused annual subscription allowance is not carried forward. Existing money already inside an ISA is different from new annual subscriptions and can often be transferred under the ISA transfer rules without being treated as a fresh subscription. You can subscribe to more than one ISA of the same type under the current rules, provided total subscriptions stay within the annual limit and each provider accepts the arrangement. Keep a running total across all providers rather than assuming each ISA has its own separate £20,000 allowance.
From 6 April 2027 under-65s get a £12,000 Cash ISA limit
HMRC's September 2026 policy paper confirms that from 6 April 2027 the annual Cash ISA subscription limit will be £12,000 for people under 65. The overall ISA limit remains £20,000, so the change restricts how much of the annual allowance can be subscribed in cash rather than cutting the total ISA allowance.
A person under 65 could therefore subscribe up to £12,000 to Cash ISAs in 2027/28 and use the remaining overall allowance in eligible non-cash ISA types. The exact split is a personal investment and savings decision; the key legal point is that cash cannot exceed the new £12,000 under-65 cap.
Do not apply the £12,000 figure to 2026/27. Articles that say the Cash ISA allowance is already £12,000 in September 2026 are a tax year early. The remaining £8,000 of the overall allowance does not become an extra Cash ISA allowance. It can be used in eligible non-cash ISA types subject to their own rules. That distinction is central to the reform and should be shown in worked examples rather than buried in a footnote.
People aged 65 or over retain a £20,000 Cash ISA limit
The 2027 reform preserves a higher Cash ISA subscription limit for people aged 65 or over. HMRC says the entitlement applies from the start of the tax year in which the person turns 65.
That means age needs to be checked against the tax year rule rather than only the date on which a Cash ISA is opened. A saver turning 65 during the relevant tax year can fall within the higher limit from the beginning of that tax year under the new framework.
The overall annual ISA limit is still £20,000, so the higher Cash ISA limit does not create an extra £20,000 on top. It simply allows the full overall annual ISA allowance to be subscribed in cash where the age condition is met. The higher cash limit is linked to age under the new rules, not to retirement status or whether the saver receives a pension. A person who meets the age condition can use the higher Cash ISA limit even if still working, while an under-65 retiree remains subject to the lower cash limit.
Worked examples across the rule change
Example one: a 40-year-old pays £15,000 into a Cash ISA on 1 October 2026. That is within the current 2026/27 overall £20,000 ISA allowance, assuming there were no other current-year ISA subscriptions using the limit.
Example two: the same person wants to subscribe £15,000 to a Cash ISA in May 2027. Under the new rules, the under-65 Cash ISA limit is £12,000, so the remaining £3,000 cannot simply be treated as another Cash ISA subscription. The person still has unused overall ISA capacity that may be used in eligible non-cash ISA types.
Example three: a saver who qualifies for the 65+ rule in 2027/28 can use up to the full £20,000 overall ISA subscription allowance in Cash ISAs, subject to the new age rule and provider eligibility. Example four: an under-65 saver who puts £10,000 into a Cash ISA in 2027/28 can still add up to another £2,000 to Cash ISAs that year, leaving up to £8,000 of the overall ISA allowance available for eligible non-cash ISA subscriptions. This makes the new cash cap easier to see as a subset of the unchanged overall limit.
Why transfers and withdrawals should not be confused with subscriptions
A subscription is new money paid into an ISA for the tax year. An ISA transfer moves existing ISA money using the formal provider process. GOV.UK says existing ISA savings can be transferred between providers without simply counting the whole transferred balance as a new annual subscription.
Withdrawals are different again. If an ISA is flexible, money withdrawn can generally be replaced in the same tax year without reducing the remaining current-year allowance in the same way. In a non-flexible ISA, withdrawing money can lose that subscription capacity for the year.
Keep three figures in your records: current-year subscriptions, transferred existing ISA money and withdrawals/replacements. Mixing them together is the easiest way to misunderstand how much new money you can still subscribe. A transfer of previous-year ISA money can be much larger than the annual subscription limit because it is moving existing sheltered money rather than adding new money. Conversely, taking cash out of a non-flexible ISA and paying it back later can use fresh subscription capacity even though the saver thinks of it as the same money.
BankOfferScout editorial view
Our editorial test for Cash ISA Allowance Explained starts with how contributions and transfers interact with the relevant tax-year rules. The page is useful only if it helps a reader compare the actual cash or access outcome, so we give more weight to rate, access, transfer mechanics and the tax-wrapper rules that apply to the money than to a single promotional number.
The strongest option is not necessarily the one with the loudest rate, reward or bonus. A better fit is the one that still works after allowing for letting a product headline substitute for the underlying wrapper rules, with recurring costs and benefits translated into a common period.
For Cash ISA Allowance, we give more weight to repeatable value than to a prominent marketing claim. The last step is freshness. Confirm subscription treatment, transfer rules and current official guidance on the provider ISA summary box, transfer terms and current product conditions; where a scheme, tax or regulatory rule matters, use HMRC or another authoritative ISA source as well. The final application, transfer or switch should always use current information.
Sources and related guides
ISA limits were checked on 30 September 2026 against GOV.UK and HMRC. Future updates must always label the tax year beside the limit. Keep the current 2026/27 £20,000 rule separate from the under-65 £12,000 Cash ISA limit that starts on 6 April 2027. Any later legislative change should be sourced from HMRC or the legislation, not inferred from provider marketing.
- GOV.UK - ISA overview and 2026/27 £20,000 limit
- HMRC - Cash ISA limit reduction from April 2027
- HMRC - September 2026 tax-free savings newsletter
- GOV.UK - ISA withdrawal rules
Related Guides: Future updates should verify both the statutory limit and the operative date. Tax-year wording matters: a rule announced or legislated in 2026 may still not apply until 6 April 2027. If HMRC changes transitional rules or age treatment, update the worked examples as well as the headline figure so the page does not contain internally conflicting years.