ISA Allowance Explained UK

ISA allowance explained (UK)

For the 2026/27 tax year (6 April 2026 to 5 April 2027), the overall adult ISA allowance is £20,000. That is the most you can subscribe across eligible adult ISAs in the year. Unused allowance does not roll into the next tax year. Cash, Stocks and Shares, Innovative Finance and Lifetime ISA subscriptions all count toward that £20,000. Junior ISAs have a separate child’s limit and sit outside the adult pot.

Lifetime ISA subscriptions are capped at £4,000 a year, and that £4,000 uses part of your £20,000. You can open a Lifetime ISA from 18 until you turn 40 and keep paying in until 50 (GOV.UK). The government adds a 25% bonus on eligible payments, up to £1,000 a year. MoneyHelper’s framing is that the bonus itself does not use the £20,000 subscription limit. LISA withdrawal rules are separate and can include penalties outside eligible first-home or age withdrawals.

Since 6 April 2024 you can subscribe to more than one ISA of the same type in a year, as long as you stay within the overall limit, though you can still only pay into one Lifetime ISA per tax year. You normally need to be 18 or over to open an adult ISA. Transitional Cash ISA access for some 16–17s ended on 5 April 2026. Under-18s generally use a Junior ISA. ISAs cannot be held jointly.

If your provider offers a Flexible ISA, you can withdraw money and replace it in the same tax year without that replacement eating extra allowance. GOV.UK’s example idea: pay in £10,000 then withdraw £3,000, and a flexible account may let you pay in another £13,000 that year. Without flexibility you may only have £10,000 of room left. Flexible ISA rules do not apply to Junior or Lifetime ISAs.

Transferring an ISA keeps money inside the tax-free wrapper when you move provider or, where allowed, type. Withdrawing the cash yourself and paying into a new ISA as a fresh subscription is different. GOV.UK warns you generally cannot treat that withdrawn amount as free extra subscription room the way a proper transfer would. Cash-to-cash transfers are expected within 15 working days. Other transfers are expected within 30 calendar days.

Interest outside an ISA may be covered by the Personal Savings Allowance: up to £1,000 for many basic-rate taxpayers, £500 for higher-rate and £0 for additional-rate (GOV.UK). Interest and gains inside an ISA do not use your PSA. For some early-career savers with modest cash balances, PSA may already cover interest outside an ISA. Larger pots and longer-term wrapping are a separate personal choice.

From 6 April 2027, the Cash ISA subscription limit will be £12,000 for people aged under 65, within the overall £20,000 annual ISA allowance. Those aged 65 and over retain the £20,000 Cash ISA limit. The regulations have now been laid before Parliament, but the current 2026/27 allowance remains unchanged. Check provider guidance before the new rules take effect.

Sprault helps you organise accounts, track savings goals and see how ISA contributions fit beside the rest of your money. Sprault provides planning tools and educational information only. It does not provide regulated financial advice or product recommendations.

Updated 5 October 2026. Source: HMRC.