ISA allowances in past tax years

The ISA allowance has been £20,000 a year for several years, and it is the same for everyone regardless of income. You can split that £20,000 across the different types of ISA in any combination, or put it all into one. What you cannot do is carry any of it forward: the allowance resets on 6 April, and whatever you have not used by 5 April is gone¹.

That reset date is the single most important thing to understand about ISA allowances. It is not a rolling 12-month window from whenever you opened your account. It is a fixed tax year, running from 6 April one year to 5 April the next, and your full allowance is available from day one³.

From 6 April 2027 the rules change for cash ISAs. The annual cash ISA subscription limit for individuals aged under 65 will be reduced to £12,000, within an overall annual ISA limit that stays at £20,000⁵. Investors aged 65 or over keep a £20,000 cash ISA limit⁶.

ISA allowances by tax year: £20,000 for the last decade

The annual ISA allowance has stood at £20,000 for several years. Official policy statements from December 2025 confirm that the annual ISA allowance will be kept at £20,000¹¹. Independent guidance published in October 2025 describes "the annual ISA limit (currently £20,000)", and guidance from December 2024 refers to "the usual £20,000 annual limit"¹².

Earlier year-by-year figures are not available here, so this page cannot set out what the limit was in any given year before that. What it can confirm is the current position and the direction of travel: the allowance has been stable at £20,000, and the government has said it will remain there¹¹.

For the 2026/27 tax year, the allowance is £20,000. You can use it in either a cash ISA or a stocks and shares ISA, or spread it across both¹⁴. Provider guidance is consistent on this: Barclays describes "this tax year's ISA allowance of £20,000", Bath Building Society states "the overall ISA allowance for the current tax year is £20,000", and Skipton confirms "your ISA allowance resets every year on 6 April"¹⁵.

The allowance is per person, not per household. If you are married or in a civil partnership, your partner has their own £20,000 ISA allowance, allowing more savings to be sheltered between you¹⁷.

How the annual allowance works across ISA types

There are four different types of adult ISA, and you can split your £20,000 allowance across them in any proportion you choose¹⁸. The four types are cash ISAs, stocks and shares ISAs, innovative finance ISAs, and Lifetime ISAs. Each has its own rules about what you can hold and when you can take money out, but they all draw on the same annual allowance.

The allowance applies to the whole tax year, from 6 April one year until 5 April in the following year¹⁹. You do not have to use it all at once. You can pay in monthly, in a lump sum, or in any pattern you like, as long as the total across all your ISAs does not exceed £20,000²⁰.

One important exception is the additional permitted subscription, or APS. This is the extra allowance a surviving spouse or civil partner can inherit when their partner dies. It is completely separate from the annual ISA allowance, and both can be used in the same tax year²¹.

Unused allowance cannot be carried forward

This is the rule that catches people out. If you do not use your full annual ISA allowance within a tax year, the allowance you do not use cannot be carried forward into the next tax year²². It is use it or lose it.

Official guidance is blunt about this: "You can't carry over unused ISA allowance into the next tax year and your allowance resets every 6 April"¹. NS&I gives the example directly: "if you deposit £10,000 one year, you cannot deposit £30,000 the next year to make up for it"².

Provider guidance says the same thing in different words. Interactive Investor states "you cannot carry it forward to the next financial year", and "any unused ISA allowance from previous tax years can't be carried forward"⁸. Barclays warns that "if you don't use your ISA allowance by the end of the tax year, you'll lose it as it won't roll over into the next year"¹⁵.

That is a pension rule and does not affect ISA allowances.

Paying in too much: what happens to the excess

If you pay more into an ISA than the annual allowance permits, the excess does not simply stay there tax-free. The additional amount may lose its tax-free status²⁴. The amount over the limit will be voided from the ISA in question, and any gain made on that amount will be taxable²⁵.

What happens next depends on the provider. Some will return the excess to you. RBS states that "if you pay in more than the limit any excess money will be returned to you"²⁶. Al Rayan Bank says it will place the excess into your nominated account²⁷. Virgin Money says that if the total you pay in exceeds the maximum annual allowance, "we'll only return" the excess²⁸.

In other cases, the extra may be moved to a different non-ISA account, and HMRC may take action or adjust your tax records²⁹. This is not a penalty in the ordinary sense, but it does mean the money loses the tax protection you were expecting.

The practical point is that overpaying is usually a mistake rather than a strategy. If you have multiple ISAs with different providers, each provider only sees its own inflows. It is your responsibility to track the total across all of them and stay within £20,000.

Changes ahead for cash ISAs and Help to Buy: ISAs

Two changes are coming that affect what you can pay in and when.

The cash ISA limit reduction. At Budget 2025, the government announced that from 6 April 2027, the annual cash ISA subscription limit for individuals aged under 65 will be reduced to £12,000⁶. This measure amends the Individual Savings Account Regulations 1998⁶. The overall annual ISA limit remains £20,000, so the remaining £8,000 can go into stocks and shares or innovative finance ISAs³⁰.

For investors aged 65 or over, the annual cash ISA limit will remain at £20,000⁶. Entitlement to the higher limit applies from the start of the tax year in which an individual turns 65⁷. NS&I confirms that if you are aged 65 or over, you are unaffected by this change and your cash ISA allowance will remain at £20,000².

Help to Buy: ISA deadlines. Existing Help to Buy: ISA holders can continue saving into their account until 30 November 2029³¹. In the first year of opening a Help to Buy ISA you can save up to £3,400, and then £2,400 each year afterwards³². The government bonus must be claimed on or before 1 December 2030³¹.

What happens to a spouse's ISA allowance when they die

When an ISA holder dies, their spouse or civil partner can inherit an additional ISA allowance. This is called an additional permitted subscription, or APS. It is equivalent to the value of the deceased partner's ISA at the date of death¹⁰.

NS&I states: "You can now inherit an additional ISA allowance if your spouse or civil partner dies, up to the value of their ISA at the date of death"⁹. The surviving spouse has a one-off additional ISA allowance equivalent to the value of the deceased partner's ISA¹⁰.

This allowance is completely separate from the annual ISA allowance, and both can be used in the same tax year²¹. So a surviving spouse could use their own £20,000 annual allowance and their inherited APS allowance in the same tax year, sheltering more than £20,000 in total.

The APS is not automatic. It must be claimed, and the rules about how and when to do so depend on the provider. No claim deadline is given here, so this page cannot state one.

Where to get help

If you are unsure how much you have paid into ISAs across different providers, or you think you may have overpaid, the first step is to contact each provider directly. They can tell you what you have subscribed in the current tax year.

For free, impartial guidance on ISAs and tax-free savings, MoneyHelper is the government-backed service. The Financial Ombudsman Service can help if you have a complaint about an ISA provider that the provider has not resolved.

If you need debt advice, organisations such as StepChange and Citizens Advice offer free, confidential help.