ISA Allowance 2026/27: What You Can Save and Rules Explained

If saving tax-free sounds like a no-brainer, you’re not alone — millions of UK savers use ISAs every year to shield their cash and investments from the taxman. But as rules shift and new changes arrive in April 2027, knowing exactly how much you can save and who can save it has never mattered more.

Current ISA allowance (2026/27): £20,000 ·
Junior ISA allowance: £9,000 ·
Tax year: 6 April to 5 April ·
Multiple ISAs allowed (since 2024): Yes ·
HMRC reporting: Annual from ISA providers

The table below provides a quick reference for the key ISA figures.

What is an ISA allowance?

The ISA allowance is the maximum amount you can save across all your ISAs in a single tax year. For 2026/27, that limit stands at £20,000, as confirmed by NS&I. You can split this across different types — cash ISAs, stocks and shares ISAs, innovative finance ISAs, and Lifetime ISAs — but the total isn’t per account, it’s per person.

Think of it as a single tax-free bucket: you choose how to fill it.

Unused allowance doesn’t roll over. Miss a year and that £20,000 is gone — no catch-up contributions allowed.

The pattern: one allowance, multiple accounts, no carry-forward. The implication: you can’t treat last year’s unused limit as a bonus — you must use it or lose it each April.

Can I put £20,000 into an ISA every year?

Yes — you can contribute up to £20,000 each tax year. Moneyfacts (financial comparison site) confirms this has been the limit since 2017/18, when it increased from £15,240. So if you’ve contributed £20,000 every year since then, you could have over £160,000 sitting tax-free.

What happens if I put in more than £20,000?

• Excess contributions may be subject to tax charges by HMRC (tax authority) via their compliance reporting
• Your ISA provider will typically reject payments over the limit
• If you accidentally exceed it, GOV.UK HMRC guidance says you must contact HMRC immediately

Can I use previous years’ unused allowance?

No. Unlike pensions, which allow carry-forward, ISA allowances reset every 6 April. Any unused £20,000 from a previous year is forfeited.

This is one of the most common misunderstandings among savers — the carry-forward rule is a key trap.

The takeaway: missing a year means losing that allowance permanently, so consistent saving matters more than trying to catch up later.

Can I open multiple ISAs?

Since April 2024, the answer is yes — and that’s a major change. Previously, you could only open one cash ISA per tax year. Now GOV.UK HMRC official rules allows you to open multiple ISAs of the same type, giving savers more flexibility.

Can I open a new cash ISA if I already have one?

• Yes — you can open multiple cash ISAs in the same tax year since 2024
• Each account shares from your single £20,000 allowance
• Yorkshire Building Society (high-street bank) notes you still must not exceed the total limit

Is it worth having two cash ISAs?

It can be — if you’re chasing better rates. Some providers offer higher interest on fixed-rate cash ISAs, while others offer easy-access. Splitting your allowance across two accounts lets you lock in a good rate on part of your savings while keeping some accessible. Hargreaves Lansdown advises checking transfer rules before opening a second account.

What happens if I accidentally open two ISAs in one tax year?

If you opened a second cash ISA before the 2024 rule change, it was invalid. Since 2024, it’s allowed — but you’re still capped by the £20,000 annual limit. MoneySavingExpert warns that accidentally exceeding the allowance across multiple accounts can trigger HMRC enquiries.

The trade-off: more flexibility but less automatic oversight. For the disciplined saver, multiple ISAs are a tool. For the forgetful one, they’re a potential HMRC headache.

Can I give my wife £20,000 to put in an ISA?

Yes — you can give money to your spouse for them to invest in their ISA. But there’s a critical rule: they must use their own ISA allowance, not yours. GOV.UK HMRC official rules confirms each person has their own allowance, and gifts between spouses are generally exempt from inheritance tax.

Can my spouse use my ISA allowance?

• No — ISA allowances are individual, not transferable
• Your spouse can only contribute to their own ISAs up to their own £20,000 limit
• If they don’t have enough income, they can still use savings you gift them — the source doesn’t matter

Are there tax implications for gifting money for an ISA?

Gifts between spouses who live together are normally exempt from inheritance tax under the spouse exemption. However, GOV.UK (HMRC ISA guidance) emphasises that the money, once in your spouse’s account, becomes their savings. If they’re a non-taxpayer and you’re a higher-rate taxpayer, the interest is taxed at their rate — a useful planning point.

The implication: for married couples, the combined household ISA allowance is actually £40,000 if both use their full limit. That’s £40,000 a year growing tax-free — a significant planning opportunity that many couples overlook.

Can I have a UK ISA if I live in Ireland?

The short answer: no — not for new contributions. GOV.UK HMRC official rules states you must be a UK resident to open an ISA. If you live in Ireland (or anywhere outside the UK), you can’t open a new ISA or contribute to an existing one — even if you’re a UK citizen.

What if I move abroad after opening an ISA?

• You can keep existing ISAs — they remain tax-free in the UK
• You cannot make new contributions while non-resident
• Income and gains may be taxable in your new country of residence

Can non-UK residents hold ISAs?

Yes — you can hold existing ISAs, but you can’t add new money. Hargreaves Lansdown advises that many providers will convert your ISA to a ‘closed’ status if you move abroad, meaning you can still manage it but can’t contribute.

ISAs are residency-dependent for contributions, not for holding.

The pattern: ISAs are residency-dependent for contributions, not for holding. The catch for expats: even if you return to the UK after years abroad, you start fresh each tax year — no backdating of unused allowances.

The challenge: residency rules create a hard boundary that catches many remote workers off guard.

Timeline: How the ISA allowance has changed

The following timeline shows how ISA allowances have evolved since 2016.

The clear trend: the overall allowance has been frozen at £20,000 for a decade. Meanwhile, the 2027 cash ISA reform breaks new ground by introducing age-based limits — a first for the ISA system.

Related reading: ISA Allowance 2025: How the £20,000 Limit Works

Frequently asked questions

For the UK saver in 2026, the choice is clear: use your £20,000 allowance while you can, but plan for the 2027 cash ISA reduction. Split across cash and stocks, or risk losing half your tax-free cash capacity come April 2027.