The ISA allowance

The ISA allowance is the amount you can pay into ISAs in your name each tax year, and it currently stands at £20,000¹. That figure is not per account: it is one allowance shared across every ISA you hold, whether cash, stocks and shares, or another type, and you can split it between them in whatever proportions suit you¹. Anything held inside an ISA then grows free of income tax and capital gains tax, and the interest or growth it earns does not eat into the allowance itself¹.

The allowance runs with the tax year, so it covers payments made between the start of the tax year in April and 5 April the following year². Anything you do not use by 5 April is lost: there is no carry-over into the following year, and a fresh £20,000 begins with the new tax year³. This page explains how the allowance works in practice, how it divides between different types of ISA, what couples can do between them, and where the limits stop.

ISA allowance: £20,000 each tax year

The annual ISA allowance is £20,000 per tax year, and this figure is confirmed consistently across providers and official documents. Ecology Building Society states the annual ISA allowance is currently £20,000 per tax year³, Shawbrook gives the same figure⁷, and Hodge Bank confirms that for the 2026/27 tax year the allowance is £20,000 across ISA products⁸. The government's own rates and allowances tables list the ISA subscription limit at £20,000⁹.

The allowance is a subscription limit, which means it counts the money you pay in, not the value of what you hold. Which? describes it as the amount you are allowed to save or invest in an ISA each year, up to £20,000¹⁰. Because it measures new money going in, an ISA can hold far more than £20,000 over time: pay in the maximum for several years, add interest or investment growth, and the balance can grow well beyond the annual figure while only ever using £20,000 of allowance per year.

One point worth knowing is that the ISA allowance is the same for everyone. Unlike many tax allowances, it does not taper or increase with your income tax band: everyone receives the same ISA allowance regardless of their income tax band¹¹. A higher-rate taxpayer and someone with no taxable income at all each have £20,000 to use. That makes the ISA unusual among tax breaks, and it is one reason the allowance is worth understanding even if you have never had a tax bill on your savings.

If you are new to ISAs generally, the section guide at ISAs: a complete guide explains what they are and how they work, and How an ISA works covers the mechanics in more detail.

The allowance runs from 6 April to 5 April

The ISA allowance follows the UK tax year, which runs from 6 April one year to 5 April the next. For the 2026/27 tax year, the £20,000 allowance covers the maximum you are allowed to pay into ISAs between 6 April 2026 and 5 April 2027². NS&I puts the same point simply: you cannot carry over unused ISA allowance into the next tax year, and your allowance resets every 6 April⁴.

This timing matters because the allowance is a use-it-or-lose-it right. The tax year ends on 5 April every year, and you must use all of your allowance by that date or lose it¹². Which? has made the same point in the context of expiring allowances: you have until 5 April to take advantage of the full amount before the new tax year begins on 6 April¹³. The practical effect is that early April is the last window for topping up an ISA with the current year's allowance, and many savers and investors make their payments in the final weeks of the tax year¹⁴.

The reset date is sometimes described in two ways: the allowance is lost after 5 April, and the new allowance begins on 6 April. Both are the same edge seen from either side, and the documents describe it both ways⁴. What is unambiguous is that there is no gap and no grace period: payments made on 6 April belong to the new tax year's allowance, even if the old one was never used.

The full detail of the year-end rush, including what to do in the last weeks before the deadline, is covered in The ISA deadline and the end of the tax year.

One allowance shared across all your ISAs

The £20,000 is a single allowance that covers all of the ISAs in your name, not a separate pot for each account. Legal & General describes the choice this gives you: you can split your ISA allowance across different types of ISAs or invest it all into one ISA account¹⁶. NS&I confirms you can split the £20,000 allowance across different types of ISAs, like cash ISAs and stocks and shares ISAs¹. So a payment of £12,000 into a cash ISA and £8,000 into a stocks and shares ISA uses the allowance exactly as fully as a single £20,000 payment into one account.

Since 6 April 2024, the rules on multiple accounts have been relaxed. Legislation was made permitting an individual to subscribe to more than one ISA account of the same type in a tax year¹⁷, and NS&I states the change plainly: the ISA rules changed on 6 April 2024, and you can now open and pay into more than one ISA of the same type in a tax year¹⁸. Before that date, you could generally pay into only one ISA of each type each year. Even now, the total across all of them remains capped at £20,000: Which? notes you can pay into different types at the same time as your cash ISA, as long as the total payments do not exceed £20,000¹⁹.

A few related limits sit alongside the main allowance. A Lifetime ISA has its own annual limit of £4,000, and payments into it count within the overall £20,000 rather than in addition to it²⁰. Junior ISAs have a separate allowance that belongs to the child, not the parent, and money in a Junior ISA does not use the adult allowance. The details are in Junior ISAs explained and How much can I put in a Junior ISA?.

The rules on paying into several ISAs in one year, including the changes since April 2024, are set out in Can I pay into more than one ISA in a year?.

How the allowance applies to cash ISAs and fixed rate ISAs

For cash ISAs, the allowance simply limits how much new money you can pay in each tax year. The money already inside, and the interest it earns, are separate matters. Which? is explicit that the interest you earn in a cash ISA does not count towards your allowance⁵. NS&I says the same about its Direct ISA: the interest you earn is tax-free, so it will not count towards your Personal Savings Allowance¹⁸. Skipton Building Society adds that interest earned from an ISA does not count towards the Personal Savings Allowance and is completely free from income tax, and that the Personal Savings Allowance is in addition to the annual ISA allowance²¹. NS&I's guidance makes the same point from the tax side: the interest you earn on ISAs and other tax-free accounts is not taxable, so it will not use up any of your Personal Savings Allowance²².

The scale of what this can mean is illustrated by a Which? example: if you paid in the full ISA allowance of £20,000, you would earn £1,154 in interest at a rate of 5.77%²³. That interest stays in the ISA, grows tax-free, and leaves the following year's £20,000 allowance untouched. The government's ISA reform factsheet confirms the principle from the official side: the Personal Savings Allowance does not apply to any growth or interest paid in an ISA⁶. Age UK's guidance agrees that savings in tax-free accounts like ISAs do not count towards the fixed tax-free allowance for savings interest²⁴.

Fixed rate cash ISAs work the same way on the allowance, with one practical difference: the money is typically locked in for a set term. A fixed rate cash ISA uses the allowance in the year you pay the money in, and the interest it accumulates over the term never touches the allowance. The trade-off is access: with the money committed for the term, a saver who wants to use a later year's allowance with fresh money needs other funds to do it. The terms, early access charges and what happens at maturity are covered in Fixed rate cash ISAs, and the comparison with fixed rate bonds outside an ISA is in Cash ISA vs savings account.

One point of caution: the cash ISA allowance is changing. From 6 April 2027, savers under 65 will be able to pay a maximum of £12,000 a year into cash ISAs within the £20,000 overall allowance⁶. Which? has reported the same change and noted that the allowance does not roll over if it is not used: instead you lose it²⁵. The full detail is in Changes to the cash ISA limit.

Couples: £40,000 between two people

ISAs are individual accounts: there is no joint ISA, and each person has their own allowance. But between them, a couple can shelter a good deal more than one person can. Legal & General notes that two people each with their own ISA accounts have a possible £40,000 combined ISA allowance¹⁶. Which? makes the same point about married couples and civil partners: your partner has their own £20,000 ISA allowance, allowing more savings to be sheltered²⁶.

There is also a route for one partner to fund the other's allowance. Which? explains that you can pay into their account instead, effectively allowing you to save up £40,000 tax-free²⁷. The same mechanism is described in its reporting on maturing cash ISAs: paying into a partner's account effectively increases your shared ISA allowance to £40,000²⁸. The allowance belongs to the account holder, not the payer, so the money is theirs once it is in the ISA, which is worth understanding clearly before making large payments into someone else's account.

The family figure in the table includes children's Junior ISAs, which carry their own separate allowances, and possibly Lifetime ISAs. The Resolution Foundation's early analysis of the Lifetime ISA noted its very high annual limit of £4,000 a year, double that for a couple, with the maximum public contribution of £1,000 (£2,000 for a couple)²⁰. Lifetime ISA payments sit within each person's £20,000 overall allowance, so a couple using two Lifetime ISAs would count £8,000 of their combined £40,000 towards Lifetime ISAs. The mechanics of the Lifetime ISA, including the government bonus, are in Lifetime ISA (LISA) explained.

Whether a couple can make use of two allowances depends on having enough money between them to fill both, and on each partner being eligible to open an ISA, which is covered in Who can open an ISA. ISAs cannot be held jointly, as explained in Can an ISA be held in joint names?.

Using the allowance before 5 April

Because unused allowance is lost at the end of the tax year, the run-up to 5 April is when many people act. Which? warns that any unused allowance does not roll over, so you need to use it by 5 April or lose it²⁹. Its end-of-tax-year checklist makes the same point: your allowance does not carry over to the new tax year, so savers and investors should make the most of the current year's allowance before it expires¹⁴.

A few practical points follow from the rules:

• Payments must be received, not just planned, by 5 April. A transfer arranged late, or a payment that clears after the year end, falls into the new tax year's allowance.
• Transfers between ISAs do not use the allowance. Which? notes the allowance is not affected by transferring money between ISAs, as long as the providers make the transfers and the money is not withdrawn⁵. The process is in How to transfer an ISA, and the rule is explained in Does transferring an ISA use my allowance?.
• Flexible ISAs can change the timing. With a flexible ISA, money withdrawn and replaced can restore allowance, which is covered in Flexible ISAs.
• Interest and growth never need topping up. Only new money from outside counts, so a saver whose ISA has grown does not need fresh allowance to keep that growth tax-free⁵.

The deadline also interacts with the coming cash ISA change. Which? has reported on whether fixing your ISA before the allowance cut makes sense, noting that to use the full £20,000 ISA allowance under the new rules, the remaining £8,000 would need to be invested in a stocks and shares ISA³⁰. Savers who want to put more than £12,000 into cash ISAs in future years may find the final tax years before April 2027 matter most, since the current £20,000 cash allowance is still available until then⁶.

Where the allowance stops: Help to Buy ISAs and other limits

The £20,000 overall limit is the headline, but several other limits and rules sit inside and alongside it. The government's consultation document on the cash ISA limit reduction confirms the structure: the ISA regulations currently provide a single overall annual ISA subscription limit of £20,000³¹. From 6 April 2027, that overall limit stays, but the cash ISA portion is capped for most savers.

The government's factsheet sets the cash ISA limit for under-65s at £12,000⁶. Family Building Society describes the split from the saver's side: of the £20,000, up to £12,000 can be paid into a cash ISA, and the remaining £8,000 would need to be invested in a stocks and shares ISA³². Which? notes the same condition in its reporting, including that under-65s would need to put £8,000 in a stocks and shares ISA to keep access to the full cash allowance³³. The stocks and shares ISA limit itself is remaining at £20,000, meaning the overall allowance is unchanged and only the cash portion is capped³⁴. Which?'s guide to stocks and shares ISA transfers likewise works from the £12,000 annual cash ISA figure when explaining what moving money between ISA types uses up³⁵.

Other limits and rules to know:

• Help to Buy ISAs are closed to new savers, but existing holders can keep saving. Which? confirms existing holders can continue to save up to £200 a month³⁶. The Help to Buy ISA scheme, its closure and the government bonus are covered in Help to Buy ISA.
• Lifetime ISAs count within the £20,000. The £4,000 annual Lifetime ISA limit is part of the overall allowance, not additional to it²⁰.
• Junior ISAs have their own allowance. A child's Junior ISA does not use a parent's allowance, as explained in Junior ISAs explained.
• Inherited ISA rights are separate. There is an additional permitted subscription that lets a surviving spouse or civil partner inherit ISA allowance, covered in Additional permitted subscription.

The over-65 position differs from the under-65 rule, and the detail is in Cash ISA Limit for Over-65s. The full changes, including when they take effect, are in Changes to the cash ISA limit.

Frozen at £20,000: what is fixed and what could change

The £20,000 allowance has been in place a long time. Which? noted in early 2024 that the current annual tax-free allowance for an adult ISA is frozen at £20,000 and has not budged since 2017³⁷. The House of Commons Library traces the origin: the increase in the annual amount an individual can save in an ISA from £15,240 to £20,000 was announced in March 2016³⁸. A parliamentary report records support for the increase in the annual ISA limit to £20,000³⁹, and TISA's guidance still describes the annual ISA limit as currently £20,000⁴⁰.

The freeze has real effects over time. Because the allowance has not risen with inflation, its value in real terms has fallen: the same £20,000 buys less shelter than it did in 2017. Which?'s reporting on frozen tax thresholds makes the general point that frozen allowances quietly cost people more as incomes and prices rise²⁹. Against that, the Personal Savings Allowance for interest outside an ISA has made ISAs less essential for some savers, a question explored in Cash ISA vs savings account.

The allowance's future has been the subject of change and debate. The Building Societies Association has warned that ISA reforms could undermine investment aims, in the context of a proposed cut in the annual cash ISA limit from £20,000 to £5,000⁴¹. The change that was actually made is narrower: the overall allowance stays at £20,000, with the cash portion capped at £12,000 for under-65s from 6 April 2027⁶. A parliamentary report states the annual ISA allowance will be kept at £20,000³⁹, and the total annual ISA allowance is set to remain frozen at £20,000 until 2030. Which?'s reporting on inheriting ISA savings also works from the usual £20,000 annual limit⁴².

Who sets the figure matters for what could change. ISA allowances are set by HMRC⁸, and changes are announced by the government at fiscal events, applying from the start of a tax year. The history of past allowances, year by year, is in ISA allowances in past tax years.

Protection, problems and where to get help

The allowance is a tax rule, and most problems around it are rule problems rather than provider failures. The commonest difficulty is breaking the subscription rules: paying in more than £20,000 across your ISAs, or paying into accounts in a way the rules did not allow. When that happens, the payment can become an invalid subscription, and there is a formal process for putting it right, covered in When an ISA subscription breaks the rules.

Other protections and routes for help:

• Cooling-off rights. If you open an ISA and change your mind, cancelling rights apply, though cancelling and re-subscribing has its own rules about the allowance. See Cancelling an ISA.
• Transfer delays. Transfers between providers must be handled by the providers, and a delayed transfer can leave money outside its tax-free wrapper. Compensation for delays is covered in Compensation if my ISA transfer is delayed.
• Complaints. If a provider gets your allowance wrong, mishandles a transfer or misapplies the rules, there is a complaints process, and unresolved complaints can go to the Financial Ombudsman Service. See Complaining about an ISA provider.
• Money held in an ISA. Protection for the money itself, including how deposits are protected if a provider fails, is explained in How your ISA is protected.

If tax on savings is the underlying question, ISAs and tax: what is tax free and what is not sets out the full picture, including how the Personal Savings Allowance interacts with the ISA allowance²¹.