Quick facts
- Annual ISA allowance (2026/27): ยฃ20,000 per person
- Junior ISA allowance: ยฃ9,000 per child
- Tax treatment: All interest, dividends, and gains are tax-free โ permanently
- Allowance resets: Every 6 April โ unused allowance cannot be carried over
An ISA shelters up to ยฃ20,000 a year from income tax and capital gains tax
Every UK adult aged 18 or over can put up to ยฃ20,000 into ISAs each tax year. Money inside an ISA is never subject to income tax on interest or dividends, nor capital gains tax on growth โ and that protection lasts forever, even as the pot grows past the original contribution. You can split the ยฃ20,000 across multiple ISA types in the same year.
Bottom line: Once money is inside an ISA wrapper, HMRC cannot touch the returns โ ever. The sooner you fill your annual allowance, the longer the tax-free compounding runs.
The four main ISA types at a glance
| Type | Best for | 2026/27 limit | Access |
|---|---|---|---|
| Cash ISA | Low-risk savers, emergency fund | Up to ยฃ20,000 (shared) | Instant or fixed-term |
| Stocks & Shares ISA | Long-term growth (5+ year horizon) | Up to ยฃ20,000 (shared) | Anytime (market price) |
| Innovative Finance ISA | Higher-risk, peer-to-peer lending | Up to ยฃ20,000 (shared) | Varies by platform |
| Lifetime ISA (LISA) | First-time buyers or retirement (under 40 to open) | ยฃ4,000 of the ยฃ20,000 | Bonuses on qualifying withdrawals only |
The Lifetime ISA earns a 25% government bonus (up to ยฃ1,000/year) but carries a 25% withdrawal penalty if used for anything other than a first home purchase or retirement at 60+. Calculate whether the bonus outweighs the penalty risk for your situation.
Bottom line: For most people over 45, a Stocks and Shares ISA or flexible Cash ISA is more useful than a LISA โ the LISA withdrawal rules can trap funds unexpectedly.
Rules to know before you invest
- One of each type per year: You can open and contribute to one Cash ISA, one Stocks and Shares ISA, one IFISA, and one LISA in a single tax year.
- Flexible ISAs: Some Cash ISAs allow you to withdraw and re-deposit in the same tax year without losing allowance โ check the "flexible" label before choosing.
- Transfers: You can transfer ISAs between providers without losing the tax-free status โ transfers must go provider-to-provider, not via your bank account.
- No UK ISA bonus in 2026: The proposed "British ISA" extra ยฃ5,000 allowance for UK equities was dropped; the total remains ยฃ20,000.
Bottom line: Use the allowance before 5 April each year โ it cannot be rolled into the next tax year, no matter the reason.
Read the official ISA rules on GOV.UKOfficial UK Government โ HMRC / GOV.UK โ
ISAs in retirement: the tax efficiency argument
Once you stop working, ISA withdrawals do not count as income โ unlike pension drawdown, which is taxed at marginal rates. This makes ISAs particularly powerful for those already in or approaching retirement.
- Withdrawals do not affect your Personal Savings Allowance (ยฃ500 for higher-rate taxpayers, ยฃ1,000 for basic-rate)
- ISA income is invisible to means-tested benefit calculations โ it does not affect entitlement to Pension Credit or age-related council tax discounts
- A Stocks and Shares ISA invested in a low-cost index fund has historically outpaced inflation over 10-year periods โ relevant for those retiring at 55โ60 who may need 30+ years of income
- You can withdraw and re-deposit in a flexible ISA without using new allowance โ useful for managing cash flow in early retirement
Bottom line: For tax planning in retirement, an ISA pot is the most flexible asset you can hold โ no forced withdrawals, no tax on growth, no income-tax drag on distributions.
This article is for information only and does not constitute financial advice. Consult a regulated financial adviser before making investment decisions.
