Best Broker for a Stocks and Shares ISA (2026)

A Stocks and Shares ISA is one of the best deals in UK investing: up to £20,000 a year, with all the growth and income inside it free of UK tax. But the platform you hold it on makes a real difference to what you actually keep, mostly through fees. Here’s how to choose, and which providers suit which investors.

What matters when choosing an ISA platform

• The fee model. UK platforms charge either a percentage of your portfolio each year or a flat fee. Percentage fees are cheap when your pot is small and expensive as it grows; flat fees are the opposite. The crossover point is the single biggest cost decision. See broker fees explained.
• What you want to hold. ETF-only investors can use the cheapest, simplest platforms. If you want funds, investment trusts or individual shares, you need a broader provider.
• Dealing costs. Some platforms charge per trade, others are commission-free. For regular investing, free or low dealing costs matter.
• Ease and service. Research, apps and customer service vary a lot, and are worth more to some people than a few pounds in fees.

Providers by what you need

A starting point, not a verdict. UK platform fees change often, so check current pricing before you commit.

• Cheapest for ETF investors: ETF-only platforms like InvestEngine, or commission-free apps like Trading 212, keep costs to the bare minimum if you only want ETFs.
• Best all-rounder: AJ Bell offers a wide range of shares, funds, ETFs and trusts at a reasonable percentage fee (with caps on shares), which suits most people.
• Best for service and research: Hargreaves Lansdown is the most polished experience, at a higher price, for those who value service over cost.
• Best flat fee for larger pots: interactive investor charges a fixed monthly fee, which tends to win once your portfolio is large enough that a percentage fee would hurt.
• Best for hands-off index investing: Vanguard, if you’re happy to stick to its own funds and ETFs.

A quick word on the rules

The ISA allowance is £20,000 across all your ISAs in a tax year, and you can transfer existing ISAs between providers without losing the tax shelter. Rules do change, so it’s worth checking the current position before you act.

The bottom line

For most long-term investors, the best ISA platform is the cheapest one that holds what you want, matched to your pot size: a percentage platform while you’re starting out, a flat-fee one once you’ve built up a larger balance. Compare the platforms by pot size with our UK ISA fee calculator, or side by side on Brokerlens.

Educational information, not personal advice. Platform fees and ISA rules change, so always check current terms. We may earn a commission if you open an account through our links, which never affects which providers we recommend.