ISA rules

Cash ISA limit: £20,000 this year, £12,000 under 65 from April 2027

Give your year of birth, say whether your birthday falls after 5 April, and enter the cash you would like to put away each year. The tool returns your cash ceiling for both tax years and the part that would not fit.

Your cash ISA limit before and after April 2027

Cash ISA limit in 2027/28

£12,000

Limit in 2026/27£20,000
Your age on 5 April 202855
Cash that will not fit in 2027/28£6,000
First year back at £20,000 in cash2037/38

Under SI 2026/1018 the £12,000 limit applies in any tax year in which you are 64 or under on 5 April.

Tax on what will not fit

In the 2026/27 tax year, ending on 5 April 2027, the whole £20,000 ISA allowance may go into cash ISAs, whatever your age. From 6 April 2027 the Individual Savings Account (Amendment) (No. 2) Regulations 2026, SI 2026/1018, cap cash ISA subscriptions at £12,000 a year for anyone who is 64 or under at the end of the tax year, which means on 5 April. For 2027/28 the test date is 5 April 2028: if you are 65 or older on that day, you keep a cash ceiling of £20,000. Someone born on 5 April 1963 is 65 that day and keeps it; someone born a day later is 64 and does not. The overall allowance stays £20,000, so an under-65 saver can still place £8,000 in stocks and shares, innovative finance or Lifetime ISAs. Cash already held in ISAs is not affected.

Sums checked by Radif Partners · Editorial policy · How the sums are done

Where the rule comes from

The lower ceiling was announced at the Budget of 26 November 2025 and is now law. SI 2026/1018 was made on 10 September 2026, laid before Parliament on 14 September 2026 and takes effect on 6 April 2027. It amends regulation 4ZA of the ISA Regulations 1998 so that a person who is 64 or under at the end of a year may subscribe only £12,000 to cash ISAs in that year. The HMRC newsletter of June 2026 set out the same design before the regulations were made.

Your ceiling by date of birth

Cash ISA ceiling in 2027/28 by date of birth. Worked out by the engine of this site from the age test of SI 2026/1018.
BornAge on 5 April 2028Cash limit 2027/28Room left for other ISAsFirst year at £20,000 cash
Born in 196067£20,000£02027/28
Born March 196365£20,000£02027/28
Born October 196364£12,000£8,0002028/29
Born February 196662£12,000£8,0002030/31
Born July 197057£12,000£8,0002035/36
Born 198047£12,000£8,0002045/46
Born 199532£12,000£8,0002060/61
Born 200819£12,000£8,0002073/74

The two rows for 1963 show how much the birthday matters. A saver born in March 1963 is already 65 on 5 April 2028 and never meets the £12,000 ceiling. One born in October of the same year is still 64 on that date, so 2027/28 is capped and the full cash allowance only returns in 2028/29. Anyone born after 5 April 1963 faces at least one year at the lower figure.

What the ceiling does not touch

The rule is about new money paid in each year. A cash ISA that already holds £80,000 built up over many years keeps all of it, and the interest on it stays outside income tax. Interest added inside the account does not count as a subscription either. Nor does the ceiling reduce the overall allowance: an under-65 saver keeps £20,000 in total, with £8,000 reserved for the other kinds of ISA. The allowance page shows how the pieces add up.

Two linked rules stop the ceiling being sidestepped. Under 65, money can no longer be moved from a stocks and shares ISA into a cash ISA, and interest on cash held inside an investment ISA meets a flat 22 % charge. Both are covered on the page on the April 2027 changes, which also works out the tax on savings that will no longer fit.

Savers close to 65

Because the test is your age on 5 April, someone who turns 65 at any point in a tax year is treated as 65 for the whole of it. The page for savers aged 65 and over goes through birth dates either side of 5 April. Residence and the minimum age of 18 for adult ISAs stay as described on GOV.UK.

To see what the interest on cash that does not fit would cost in tax at your income, run the full ISA against taxable account calculator.

Questions savers ask

Is the £12,000 cash ISA limit per account or per person?

Per person and per tax year. It covers everything you pay into all your cash ISAs together, even if they are with different banks or building societies. Paying £6,000 into each of two cash ISAs uses the whole £12,000 for someone under 65 in 2027/28. The overall £20,000 allowance still applies on top as a separate ceiling.

Which day decides whether I get the £12,000 or the £20,000 cash limit?

The last day of the tax year, 5 April. The regulations ask whether you are 64 or under at the end of that year, not on the day you pay in. A person who turns 65 in January 2028 is 65 on 5 April 2028 and so has the higher ceiling for the whole of 2027/28, including deposits made in the summer of 2027 while still 64.

Can I still pay £20,000 into a cash ISA before April 2027?

Yes. The lower ceiling only starts with the 2027/28 tax year on 6 April 2027. Until 5 April 2027 the full £20,000 can go into cash ISAs at any age, and whatever is paid in during that time stays tax free in later years. The new rules do not reach back to money already held in a cash ISA.

Does the cash limit apply to a Junior ISA held by a teenager?

No. A Junior ISA has its own allowance of £9,000 a year, which can be held in cash in full. The adult cash ceiling starts once the young person holds adult ISAs, which is only possible from 18. An 18-year-old in 2027/28 is well under 65, so the adult cash ceiling for them is £12,000.

Next sums to try

Cash ISA changes 2027

The whole April 2027 reform in one place: dates, the £12,000 ceiling, the transfer ban, the 22 % charge.

ISAs over 65

Whether your date of birth keeps the £20,000 cash ISA limit in 2027/28, and from which year.

ISA allowance

How much of the £20,000 you have used this year, and how much of it can still go into cash.

£20,000 of savings

One full ISA allowance in cash: what fits in 2026/27, what fits from 2027/28 and what the rest costs in tax.

Laws and official pages behind this page

Worked out by

Independent publisher of ISA and savings tax calculators for the United Kingdom

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Tax year 2026/27 (6 April 2026 to 5 April 2027), with the 2027/28 rules already in law, rules last read on . Worked out from the rules in law on the date shown; not financial advice, and no product is recommended.