What is a Stocks and Shares ISA? Types, providers, fees, and how they work

Key points

This article is for information only and does not constitute financial advice.

With new ISA rules coming into force in 2027, interest in Stocks and Shares ISAs is surging.

Ministers and regulators have been increasingly vocal about the UK’s ‘cash-heavy’ savings culture, warning millions are losing out in real terms as inflation erodes the value of cash savings.

Against that backdrop, Stocks and Shares ISAs are being positioned as a key way for households to build long-term wealth. But they remain widely misunderstood. From how they work and what you can invest in, to fees, risks and whether you can hold one alongside a Cash ISA, here’s what UK savers need to know.

What is a stocks and shares ISA

A Stocks and Shares ISA is a tax-efficient investment account that allows you to invest your money while shielding any returns from tax. You don’t pay income tax on dividends, and you don’t pay capital gains tax if your investments grow in value.

Unlike a Cash ISA, where your money earns interest, a Stocks and Shares ISA lets you invest in assets such as shares, funds and bonds, meaning returns are linked to market performance rather than a fixed rate.

This distinction has become more important as inflation has repeatedly outpaced many savings rates.

NimbleFins analysis shows how inflation can quietly eat away at ISA savings over time, even when interest is being paid.

Stocks and Shares ISA limit

The annual ISA allowance for 2026 remains at £20,000 per person. This is the maximum you can put into ISAs across all types in a single tax year, whether that’s Cash, Stocks and Shares, Lifetime ISAs, or a combination.

But more people are likely to start investing in Stocks and Shares ISAs from April 2027 after the Government reduced the allowance for Cash ISAs.

While the overall allowance will remain at £20,000, savers will only be able to save up to £12,000 in a Cash ISA from April 6 2027.

Savers can decide to put however much they want into a Stocks and Shares ISA up to a maximum of £20,000 a year.

For a full breakdown of how the allowance works and what’s changing, see our article: **How to beat the Cash ISA allowance cut as half of savers risk higher tax bill.

Can you have a Cash ISA and Stocks and Shares ISA?

Yes, you can hold both a Cash ISA and a Stocks and Shares ISA at the same time, as long as your total contributions across all ISAs don’t exceed the £20,000 annual limit.

This flexibility is increasingly being highlighted by policymakers as part of the 2027 reforms, with savers encouraged to keep short-term money in cash while investing longer-term funds for growth.

NimbleFins compares the pros and cons of each option in more detail here: Cash ISAs vs Stocks & Shares ISAs: Which is best?.

How does a Stocks and Shares ISA work?

When you open a Stocks and Shares ISA, you choose an investment platform or provider. You then decide how your money is invested, either by selecting funds, buying individual shares, or using ready-made portfolios.

Your investments can rise and fall in value. Unlike cash savings, returns are not guaranteed, which is why Stocks and Shares ISAs are typically used for medium- to long-term goals - typically five years or more – due to short-term fluctuations.

Stocks and Shares ISA returns

Returns depend on what you invest in and how markets perform. Historically, stock market investments have tended to show higher long-term growth than cash savings, though outcomes vary and are not guaranteed.

The Government’s thinking in 2026 is that while investing carries ups and downs, keeping money in low-interest cash for decades can also come at a cost, especially for younger workers who are likely to be saving for the long term.

Looking at long-term data, broad UK stock market indices show prices have risen by several hundred percent over the past few decades, although returns have not been smooth and there have been significant periods of decline.

To give a sense of scale, long-term data for broad UK share markets suggests that £1,000 invested around 20 years ago could be worth roughly £3,000–£4,000 today if returns were reinvested, although this growth would not have been steady and would have included periods of sharp decline.

By comparison, cash savings over the same period would typically have delivered much lower growth once inflation is considered. Using an average Cash ISA interest rate of 2.5% over the past two decades, £1,000 saved in a Cash ISA and left untouched would likely be worth around £1,600–£2,000 today, assuming interest was reinvested.

The difference reflects long periods of low interest rates, particularly following the financial crisis and during the pandemic, when many Cash ISAs paid returns that struggled to keep pace with rising prices.

It’s worth nothing that these examples are illustrative and do not predict future returns.

Our stock market calculations are based on FTSE 100 figures showing a total shareholder return of around 240% over the past 20 years, meaning £1,000 invested across the market would have grown to around £3,400 over that period if dividends were reinvested.

Our Cash ISA returns figure was based on an average interest rate, balancing out the high rates in the mid-2000s, the low rates post 2008, and an uptick since 2020.

By our calculations, using compound interest over 20 years:

How many Stocks and Shares ISAs can I have?

You can open multiple Stocks and Shares ISAs, but you can usually only pay into one of each ISA type per tax year.

Some flexibility exists around transfers and inherited ISAs, which can complicate matters, particularly when dealing with bereavement and Additional Permitted Subscriptions.

For more on APS, see our explainer article here..

Types of Stocks and Shares ISA

There are several ways to invest within a Stocks and Shares ISA, and the best option for you is not an exact science, and can depend on experience and confidence.

Here is a breakdown of the different types of Stocks and Shares ISAs

Funds and ready-made portfolios are commonly offered by platforms as options requiring less direct involvement than choosing individual shares.

Compare different Stocks and Shares ISA providers

Providers differ significantly on fees, ease of use, investment choice and customer satisfaction.

Some platforms charge a percentage fee, while others charge flat monthly costs, which can make a big difference depending on how much you invest.

When comparing the best Stocks and Shares ISA for you, ratings and reviews can be useful, particularly for beginners who value good customer support and intuitive apps.

How to open a Stocks and Shares ISA

Opening a Stocks and Shares ISA is usually done online and can take as little as 10–15 minutes. You’ll need to provide personal details, verify your identity, and choose how you want to invest.

Many platforms allow you to start with a lump sum or regular monthly contributions.

Can I transfer my Cash ISA to a Stocks and Shares ISA?

Yes, you can transfer some or all of a Cash ISA into a Stocks and Shares ISA without losing its tax-free status, as long as you use the official ISA transfer process.

This option has been heavily discussed in 2026 as part of efforts to move dormant cash into higher-growth assets, though it’s important to remember that once invested, money is exposed to market risk. If you need to withdraw your savings for an emergency there is a risk the market will not be performing well at the time and you could lose some of your investments.

Stocks and Shares ISA and Lifetime ISA

A Lifetime ISA (LISA) is a specific type of ISA designed to help people save for either their first home or retirement. You can contribute up to £4,000 a year into a LISA, and the Government adds a 25% bonus on top — up to £1,000 per year. Any money paid into a LISA counts towards your overall £20,000 annual ISA allowance.

Unlike a standard Stocks and Shares ISA, a LISA comes with strict rules around when money can be withdrawn. Funds can usually only be taken out without penalty to buy a first home (up to a set price limit) or from age 60. Withdrawing money for any other reason typically triggers a Government withdrawal charge, which can leave you with less than you put in.

It’s possible to hold both a Stocks and Shares ISA and a Lifetime ISA at the same time. Some people use a Stocks and Shares ISA for more general, flexible investing, while treating a LISA as a more tightly controlled pot for specific long-term goals. The key difference is flexibility: money in a Stocks and Shares ISA can usually be accessed at any time, whereas LISA withdrawals are restricted.

NimbleFins explains how LISAs work, including penalties, here: "Lifetime ISA explained".

What platforms offer the lowest fees for Stocks and Shares ISA?

Fees can vary significantly and may have a greater impact over longer investment periods, because charges are deducted year after year regardless of how markets perform. Most Stocks and Shares ISA platforms charge either a percentage-based fee, a flat annual fee, or a combination of both, alongside the fees charged by the underlying investments.

Many investors use broad, low-cost index funds, which aim to track the performance of a market rather than beat it. Popular examples often cited in UK investment data include funds that track the FTSE All-Share, FTSE 100 or global equity markets. These types of funds typically have ongoing charges of around 0.1% to 0.25% a year, meaning £1 to £2.50 annually for every £1,000 invested.

Other commonly used options include actively managed funds, where a fund manager selects investments in an attempt to outperform the market. These usually come with higher ongoing charges, often between 0.6% and 1% a year, reflecting the cost of active management.

On top of fund fees, platforms apply their own charges. Percentage-based platforms often charge around 0.2% to 0.45% a year on the value of investments, while flat-fee platforms may charge a fixed monthly or annual amount regardless of portfolio size. As a result, flat fees tend to take up a larger share of smaller balances, but a smaller share of larger portfolios.

The total cost of a Stocks and Shares ISA therefore depends on both the platform fee and the fees of the investments held, which is why charges can differ substantially between providers even when investing in similar markets.

Fees shown are typical ranges and may change over time. All figures are for information only and do not represent recommendations.

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