Cash ISA vs Stocks and Shares ISA: Which Should You Choose?

An ISA (Individual Savings Account) is simply a wrapper that lets your money grow free of UK tax. You don't pay tax on the interest, dividends or gains inside it. The catch is that there's a yearly limit — and several types to choose from. Here's how to pick.

The one rule that ties them all together

For the 2026/27 tax year you can pay in up to £20,000 across all your ISAs combined — a figure that has been frozen since 2017/18. You can split it however you like (say, some in a Cash ISA and some in a Stocks & Shares ISA), but you can't exceed £20,000 in total. The allowance resets each 6 April and you can't carry unused allowance forward. The official rules live on GOV.UK.

Cash ISA — safety and certainty

A Cash ISA works like a normal savings account, but the interest is tax-free. Your capital doesn't fall in value, and deposits are protected up to £120,000 per person, per banking institution, by the FSCS. It's ideal for money you might need soon or can't afford to risk. The trade-off: over many years, cash returns can struggle to keep pace with inflation.

Stocks & Shares ISA — growth, with risk

A Stocks & Shares ISA holds investments — funds, shares, bonds — instead of cash. Historically, investments have outpaced cash over the long run, but their value rises and falls and you could get back less than you put in. Inside the ISA, any growth is free of Capital Gains Tax and dividends are free of dividend tax, which matters once you're investing beyond the modest CGT allowance (£3,000) and dividend allowance (£500). It suits money you can leave invested for at least five years.

Lifetime ISA — a 25% bonus, with strings

A Lifetime ISA (LISA) is built for two specific goals: buying a first home or saving for retirement. You can pay in up to £4,000 a year (this counts toward your £20,000 allowance) and the government adds a 25% bonus — up to £1,000 a year free. You must be 18–39 to open one and can pay in until age 50. The money is for a first home worth up to £450,000, or withdrawal from age 60. Take it out for any other reason and you pay a 25% penalty, which claws back the bonus and a little extra. Full rules are on GOV.UK.

Innovative Finance ISA — niche and higher-risk

An IFISA holds peer-to-peer loans and similar debt-based investments. Returns can be higher, but so is the risk, and your money generally isn't covered by the FSCS deposit protection that applies to cash. It's a specialist choice for experienced investors.

*Shares the single £20,000 overall allowance; the LISA's £4,000 also counts toward it.

Do you even need a Cash ISA?

Thanks to the Personal Savings Allowance, basic-rate taxpayers can already earn £1,000 of interest tax-free outside an ISA each year (£500 for higher-rate, £0 for additional-rate). If your savings interest sits comfortably under that, a top-rate ordinary savings account may beat a Cash ISA. The ISA wins when you're near or over your allowance, or want to protect money from tax for the long term.

How to choose

• Need it within ~5 years? Lean Cash ISA (or a top ordinary account if you're under your PSA).
• Investing for 5+ years and can stomach ups and downs? A Stocks & Shares ISA has historically rewarded patience.
• Saving for a first home and aged under 40? The LISA's 25% bonus is hard to beat — just respect the lock-in.

For impartial, government-backed explainers, MoneyHelper is an excellent next stop. And if you're weighing where non-ISA cash should sit, read our guide to where to put your savings.