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Tax-free saving

Make the most of your ISA.

ISAs let your savings and investments grow tax-free, up to £20,000 a year. Here’s how they work, the changes coming in 2027, and what to weigh when choosing one.

Tax-free growth

Money held in an ISA grows free of UK income tax and capital gains tax — interest, dividends and gains are all sheltered inside the ISA wrapper.

Stocks & Shares options

A Stocks & Shares ISA lets you invest in funds, shares and ETFs with the same tax-free treatment — with the trade-off that investments can fall as well as rise.

Fees worth comparing

Platform and fund charges vary widely between UK ISA providers. Understanding how the fees are structured helps you keep more of what you save.

What is an ISA?

An Individual Savings Account (ISA) is a government-backed “tax wrapper”: money you hold inside one grows free of UK income tax and capital gains tax. For the 2026/27 tax year you can pay in up to £20,000 in total, split across cash, stocks & shares and innovative finance ISAs however you like.

For early retirement planning, the Stocks & Shares ISA is often the one of interest: it sits alongside a pension as a tax-free pot you can access at any age, without the pension rules on when you can draw it. The trade-off is investment risk — the value can fall as well as rise — so it suits money you can leave invested for the longer term.

One change worth planning around: from 6 April 2027, the amount under-65s can put into a Cash ISA each year is set to fall from £20,000 to £12,000, with the rest of the allowance available for stocks & shares. The overall £20,000 ISA allowance stays the same, and over-65s keep the full cash limit.

Affiliate disclosure. Some links on Retire57 are affiliate links — if you open an account or buy a product through them, Retire57 may earn a commission at no extra cost to you. This never changes what is written here, and it is not a recommendation: always compare options and decide what is right for your own circumstances.
Common questions

ISAs, answered.

Who can open a Stocks & Shares ISA?

UK residents aged 18 or over can open a Stocks & Shares ISA.

What is the annual ISA allowance?

For the 2026/27 tax year the ISA allowance is £20,000. This is the total you can pay in across all your ISAs in the year — the allowance resets each 6 April and can't be carried forward.

Can I pay into more than one ISA?

Yes. Since April 2024 you can pay into multiple ISAs of the same type in the same tax year, and split your £20,000 allowance across cash, stocks & shares and innovative finance ISAs in any combination — as long as the total stays within £20,000. (Lifetime ISAs have their own £4,000 limit within that overall allowance.)

Is the Cash ISA allowance changing?

Yes — this is worth knowing if you're planning ahead. From 6 April 2027, the amount under-65s can pay into a Cash ISA each year is set to reduce from £20,000 to £12,000, with the remaining allowance usable in stocks & shares. Those aged 65 and over keep the full £20,000 cash limit. The overall £20,000 ISA allowance itself stays the same.

Are there fees with an ISA?

Fees vary by provider — typically a platform charge plus any fund costs. Comparing fee structures across providers is one of the simplest ways to improve your long-term returns.

Is money in a Stocks & Shares ISA at risk?

Yes. Investments can go down as well as up, so the value of a Stocks & Shares ISA may be less than you put in. A Cash ISA doesn't carry that investment risk, but returns are typically lower.

How do I choose an ISA provider?

Weigh fees, the range of investments offered, ease of use and service. What's right depends on your own circumstances — and this isn't a recommendation of any particular provider.

Go deeper

ISA guides.

ISAs

ISA fundamentals: the basics to empower your savings

ISAs

How Stocks & Shares ISAs can grow your investments

ISAs

Understanding the fee models of top UK ISAs

Figures correct as of March 2026. Tax rules, allowances and rates change over time — always check the current position before acting.