ISAs · September 2026
ISAs for Beginners: A Simple UK Guide
Capital at risk. The value of investments can fall as well as rise, and you may get back less than you put in. Past performance is not a guide to future returns.
FSCS protects eligible deposits up to £120,000 per person, per authorised institution.
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Quick answer
- An ISA is a tax wrapper. What you hold inside it is a separate choice.
- There are five types of ISA, each with different rules and risks.
- The adult allowance is £20,000 for 2026/27 (check GOV.UK), and it doesn’t roll over.
- Use the official transfer process to move an ISA, rather than withdrawing and paying back in.
An ISA is a tax-free wrapper, not a product
You may keep hearing “put it in an ISA”. An ISA (Individual Savings Account) is a way of holding savings or investments so that the interest, dividends and gains are free of UK tax.
Think of the ISA as the wrapper: it gives the tax treatment. What sits inside it, whether that is cash, funds or shares, is a separate choice.
This guide explains what an ISA is, what tax-free means, the five types of ISA, the yearly allowance, flexible ISAs, moving an ISA, protection and risk, common mistakes and some frequently asked questions. It is general information about how ISAs work. It is not advice to open any type of ISA or any provider’s account.
What an ISA is
- An ISA is a type of account set up by the government. Banks, building societies, investment platforms and other providers approved by HMRC offer them.
- ISAs are for UK residents. Minimum ages differ by type: 16 or over for a Cash ISA at present, and 18 or over for most other adult ISAs (check GOV.UK).
- Each ISA is held in your own name only. There are no joint ISAs. If you want to save with someone else, see joint savings accounts.
- The tax benefit stays with the money only while it stays in an ISA, or moves using the official transfer process (see moving an ISA).
“ISA” describes the tax treatment, not the investment. A Cash ISA and a Stocks and Shares ISA share the same tax benefit, but what is inside them, and the risks, are very different.
“Tax-free” explained simply
Inside an ISA, there is no UK Income Tax on interest, no tax on dividends and no Capital Gains Tax on investment growth. You also don’t need to report ISA income on a tax return.
You might wonder why this matters if you pay little tax on your savings today. Outside an ISA, many savers are already covered by allowances such as the Personal Savings Allowance, the starting rate for savings and the dividend allowance.
The current amounts are on GOV.UK. The benefit of an ISA can grow as your balance, interest rates or income rise, and money kept in an ISA stays tax-free year after year.
Tax-free does not mean risk-free. It says nothing about how much you will earn or whether your money is protected. That is covered in the section on protection and risk.
Imagine two savers who each leave the same amount to grow for many years. One pays tax on part of the growth each year, and the other holds it in an ISA.
Because nothing is taken out for tax, the ISA saver’s growth can itself grow, so the gap between them tends to widen over time. See compound interest explained for how this works.
The five types of ISA
Cash ISA
- Holds cash savings that earn interest.
- Comes in easy-access, notice and fixed-term versions.
- Deposits are covered by FSCS protection (see below).
- Compare interest using AER. See AER explained.
Stocks and Shares ISA
- Holds investments such as funds, shares, investment trusts and bonds.
- The value can go down as well as up.
- Platform and fund fees apply. See Stocks and Shares ISA fees.
- Generally treated as a longer-term option, because investments can fall in the short term.
Lifetime ISA (LISA)
- You can open one if you are aged 18 to 39, and pay in up to £4,000 a year until you turn 50. This counts towards your overall ISA allowance.
- The government adds a 25% bonus to what you pay in.
- The money is for buying a first home (with a property price cap of £450,000) or for use from age 60.
- Taking money out for any other reason usually means a 25% government withdrawal charge, unless you are terminally ill. This can mean getting back less than you paid in.
Check all Lifetime ISA figures, the property price cap and any announced changes on GOV.UK before you act. Full detail: Lifetime ISA rules.
Innovative Finance ISA (IFISA)
An Innovative Finance ISA holds peer-to-peer loans and certain crowdfunding debt. It is higher risk. Your money can be tied up for a long time or lost if borrowers do not repay, and it is not covered by FSCS deposit protection.
Junior ISA (JISA)
- For under-18s. A parent or guardian opens it, and it can be a Cash or a Stocks and Shares Junior ISA.
- The child cannot withdraw the money until they turn 18, when it becomes an adult ISA.
- The limit for 2026/27 is £9,000, separate from the adult allowance (check GOV.UK).
- More in our Junior ISAs guide.
Providers only offer some of these types, and some ISAs are sold as “flexible” (see flexible ISAs).
ISA types at a glance
| ISA type | What it holds | Who can open one | Yearly limit | Access to money | Main risk | FSCS position |
|---|---|---|---|---|---|---|
| Cash ISA | Cash savings | UK residents aged 16+ | Part of £20,000 | Depends on the account (easy access, notice or fixed) | Inflation can reduce buying power | Deposit protection up to £120,000 per institution |
| Stocks and Shares ISA | Funds, shares, bonds | UK residents aged 18+ | Part of £20,000 | You can usually sell and withdraw (check terms) | Value can fall | Covers firm failure only, not falls in value |
| Lifetime ISA | Cash or investments | Opened at ages 18 to 39 | £4,000 within £20,000 | First home or age 60, otherwise a 25% charge | Withdrawal charge, plus investment risk if invested | Depends on whether it holds cash or investments |
| Innovative Finance ISA | Peer-to-peer loans | UK residents aged 18+ | Part of £20,000 | Can be hard to access | Borrowers may not repay | Generally not FSCS-protected |
| Junior ISA | Cash or investments for a child | Under-18s (opened by a parent or guardian) | £9,000 (separate) | Locked until 18 | Depends on type | Same as the Cash or Stocks and Shares row |
Figures are for 2026/27 and are shown to explain the rules, not to suggest a choice. Check allowances and age rules on GOV.UK and protection limits on FSCS before you act.
The ISA allowance: how much you can put in
The adult ISA allowance for the 2026/27 tax year (6 April 2026 to 5 April 2027) is £20,000 (check GOV.UK before you act).
- It is one allowance shared across all your adult ISAs, and you can split it between types. The Lifetime ISA’s £4,000 sits within the £20,000.
- The Junior ISA allowance is separate and belongs to the child.
- The allowance does not roll over. Anything unused is lost at the end of the tax year on 5 April.
- Since 6 April 2024, you can pay into more than one ISA of the same type in a tax year, within the overall allowance. The exceptions are that you can pay into only one Lifetime ISA per tax year, and a child can hold only one Cash Junior ISA and one Stocks and Shares Junior ISA.
- Money you take out of a non-flexible ISA still counts towards that year’s allowance.
The government has announced that from 6 April 2027, the amount people under 65 can put into Cash ISAs will be capped at £12,000 within the £20,000 overall allowance. People aged 65 and over would keep the full £20,000 for cash. This is not current law.
It depends on legislation and final HMRC rules, and nothing changes for 2026/27. It does not cap Stocks and Shares ISAs. Further details may follow, so check GOV.UK closer to April 2027.
One allowance, many pots
This example shows how one £20,000 allowance could be split. It is an illustrative split, not a recommendation.
Figures are for 2026/27. Check GOV.UK.
For the full rules, see ISA allowance rules.
Flexible ISAs and taking money out
You can usually take money out of a Cash or Stocks and Shares ISA, subject to the account’s own terms, such as notice periods or penalties on fixed-term accounts. Lifetime ISAs and Junior ISAs have their own restrictions, set out above.
A flexible ISA lets you take money out and put it back in the same tax year without using up more of your allowance. Not every ISA is flexible. It is the provider’s choice, so check the account terms.
You pay in £5,000, take out £2,000, then pay the £2,000 back later in the same tax year. In a non-flexible ISA, you have used £7,000 of your allowance. In a flexible ISA, you have used £5,000.
Any money you replace must go back in before 5 April of the same tax year. Check the current flexible ISA rules on GOV.UK.
If you might need to dip into your ISA and top it back up, flexibility decides whether that costs you allowance. It is a feature of the account, so look for it in the terms rather than assuming.
Moving an ISA: use the official transfer process
You can move ISA money to another provider, or between ISA types, without losing its tax-free status, as long as you use the official ISA transfer process. You ask the new provider to arrange it.
Never withdraw cash yourself when transferring an ISA — always use your new provider’s official ISA transfer service to preserve your tax-free status.
If you withdraw the money and pay it in yourself, it loses its ISA status. Paying it back in counts as a new subscription and uses up allowance.
- Money from previous tax years can usually be moved in full or in part.
- Money paid in during the current tax year can also be moved in part, following a rule change from April 2024 (check GOV.UK), subject to provider rules.
- Before you move, check for exit fees, fixed-term penalties and whether the new ISA accepts transfers in. Transfer timescales are set out in HMRC guidance.
- Moving from a Cash ISA to a Stocks and Shares ISA changes the risk you are taking, because investments can fall in value.
- The announced 2027 changes may affect transfers between ISA types. Check GOV.UK for confirmed details.
In a transfer, the money moves directly between providers, so it never leaves the ISA wrapper. That is what keeps its tax-free status and stops it counting against this year’s allowance again.
Step-by-step detail: How to transfer an ISA.
Is my money protected? FSCS and investment risk
Cash ISAs
Cash ISAs are covered by Financial Services Compensation Scheme (FSCS) deposit protection up to £120,000 per person, per authorised bank or building society. This is the limit from 1 December 2025 (check FSCS). Brands that share one banking licence share one limit.
The limit applies across all your deposits with that bank or building society, not once for each ISA. More in FSCS protection limits.
Stocks and Shares ISAs
FSCS does not protect you if your investments fall in value. It may cover you if an authorised investment firm fails and your money or investments are missing, up to its investment protection limit. Check the current limit on FSCS.
Innovative Finance ISAs
Peer-to-peer loans are generally not FSCS-protected. If borrowers do not repay, you could lose money.
Cash is not risk-free either. Inflation can reduce what your savings will buy over time. See inflation explained.
The catch
Common beginner mistakes
- Withdrawing money and paying it into a new ISA yourself instead of using a transfer, which loses the tax wrapper or uses up allowance.
- Assuming unused allowance carries over, and missing the 5 April deadline.
- Paying in more than £20,000 across all your ISAs in one tax year. If this happens, HMRC may contact you and the extra may be corrected. It is usually sorted out, but it is easier to keep track of what you pay in.
- Thinking “tax-free” means “safe”, or putting money you need soon into a Stocks and Shares ISA without understanding the risk.
- Taking money out of a Lifetime ISA for a non-qualifying reason and paying the withdrawal charge.
- Not checking whether an ISA is flexible before taking money out.
- Leaving money in an old ISA without reviewing its current rate or fees.
- Keeping more than the FSCS limit with one banking group without realising.
- Believing the announced 2027 Cash ISA change already applies.
Key takeaways
- Check protection and risk before you choose a type.
FAQ
Can I have more than one ISA?
Yes. You can hold several ISAs and, since 6 April 2024, you can pay into more than one ISA of the same type in a tax year, as long as the total stays within your overall allowance. There are two exceptions. You can pay into only one Lifetime ISA per tax year, and a child can hold only one Cash Junior ISA and one Stocks and Shares Junior ISA. Check the current rules on GOV.UK.
Do I need to tell HMRC about my ISA?
Usually not. Interest, dividends and gains inside an ISA are free of UK tax, so they do not go on a tax return.
What happens to my ISA if I move abroad?
You can usually keep your ISA and its tax-free status in the UK, but you generally cannot pay new money into it while you are not UK resident. Tax rules in your new country may treat it differently. Check the current rules on GOV.UK.
Is a Cash ISA worth it if I’m under my Personal Savings Allowance?
It depends on your situation. If your savings interest is already covered by the Personal Savings Allowance, a Cash ISA may not save you any tax today. Some people still use one because interest rates, balances and income can change over time, and ISA savings stay tax-free year after year. Others prefer to compare all savings accounts on rate and access alone. There is no single right answer for everyone.
Can I open an ISA for my child?
Yes, through a Junior ISA. A parent or guardian opens it, anyone can pay in up to the yearly limit, and the child cannot take the money out until they turn 18. The limit for 2026/27 is £9,000 (check GOV.UK).
More on saving for children: Junior ISAs and kids’ savings.
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