Best Stocks & Shares ISA Platforms UK (2026)
A Stocks & Shares ISA lets UK residents invest up to £20,000 per tax year completely free from Capital Gains Tax and Income Tax on returns. Choosing the right platform depends on your portfolio size, how hands-on you want to be, and what you want to invest in.
We compare the best ISA platforms available to UK investors in 2026 — ranked on fees, investment choice, ease of use, and overall value. We review and update this comparison regularly to reflect changes in fees and platform offerings.
Independent UK comparison · Updated regularly · Fee data sourced from provider schedules · Focused on UK investors only · Affiliate disclosure
Best ISA Platforms — Our Top Picks
Popular ISA comparisons on InvestCompareUK: Trading 212 vs Interactive Investor · Interactive Investor vs AJ Bell · Cheapest ISA Platforms UK
Trading 212
Zero platform fee, zero commission, fractional shares from £1 and a 0.15% FX fee — one of the lowest in the UK. The default recommendation for most UK beginners and cost-conscious investors at any portfolio size.
InvestEngine
Zero platform fee on DIY ETF portfolios. You only pay the underlying ETF fund charges — typically 0.03%–0.20% per year. The most cost-effective way to build a passive ETF portfolio in a Stocks & Shares ISA.
Interactive Investor
Flat £11.99/month fee regardless of portfolio size. For larger portfolios, this becomes significantly cheaper than percentage-fee platforms. Wide fund range, investment trusts, and one free trade per month included.
AJ Bell
0.25% annual platform fee, capped for larger portfolios. Wide fund selection, investment trusts, and a solid mobile app. Good balance of cost and investment range for medium-sized portfolios.
Nutmeg
Fully managed portfolios — answer a few questions and Nutmeg invests on your behalf based on your risk level. Higher fees than DIY platforms, but removes all investment decisions. Good for hands-off investors.
Key Trade-Offs — Pick Your Priority
Every platform involves a trade-off. Here's what you're actually choosing between:
Choose Trading 212 if cost is everything
- Lowest possible platform cost at every portfolio size
- Trade-off: more limited research tools than full-service brokers
- No access to investment trusts or managed funds
Choose InvestEngine if you want ETFs only
- Zero platform cost on DIY ETF portfolios
- Trade-off: no individual stocks, no actively managed funds
- Best combined with a separate account for stock picking
Choose Interactive Investor if your portfolio is large
- Flat fee saves significant money above ~£50,000
- Trade-off: expensive for smaller portfolios (£143.88/year minimum)
- Wide fund range and investment trusts included
Choose Nutmeg if you want zero decisions
- Fully managed — no investment knowledge required
- Trade-off: you are paying materially higher annual fees to avoid making your own investment decisions
- Useful only if you genuinely will not make your own investment decisions
ISA Platform Fee Comparison
Platform fees only — trading fees and underlying fund charges (OCF) are additional. Always verify current fee schedules directly with each platform before opening an account.
| Platform | Fee Model | £10,000 | £50,000 | £100,000 | Best For |
|---|---|---|---|---|---|
| Trading 212 | 0% | £0 | £0 | £0 | Beginners, all sizes |
| InvestEngine (DIY) | 0% platform | £0 | £0 | £0 | ETF investors |
| Freetrade | £4.99/mo flat | £59.88 | £59.88 | £59.88 | £20k+ portfolios |
| Interactive Investor | £11.99/mo flat | £143.88 | £143.88 | £143.88 | £50k+ portfolios |
| AJ Bell | 0.25%/year | £25 | £125 | £250 | Medium portfolios |
| Hargreaves Lansdown | 0.35%/year | £35 | £175 | £350 | Full-service investors |
| Nutmeg | 0.75%/year (managed) | £75 | £375 | £750 | Hands-off managed |
Platform fees only. These examples exclude fund OCFs, FX charges, and dealing commissions where applicable. Figures are illustrative estimates based on current published fee structures — always verify current fees directly with each provider before opening an account. See our full cheapest ISA platforms guide for a detailed breakdown.
Best ISA Platform by Use Case
Not sure which platform fits your situation? Here's the short answer for each type of investor.
Best ISA for beginners
- Trading 212 — zero fees, simple app, fractional shares from £1
- No prior investing knowledge needed
- Also see: Best ISA for beginners guide
Best ISA for ETF investing
- InvestEngine — zero platform fee on DIY ETF portfolios
- Only pay the underlying fund charges
- ETFs only — no individual stocks
Best ISA for larger portfolios (£50k+)
- Interactive Investor — flat £11.99/month fee
- Cheaper than percentage-fee platforms at scale
- Wide fund range and investment trusts
Best managed / hands-off ISA
- Nutmeg — fully managed by risk level
- No investment decisions required
- Higher fees than DIY platforms
Best ISA for fund investors
- AJ Bell — 0.25%/year, wide fund range
- Good balance of cost and investment choice
- Suits medium-sized portfolios well
Cheapest Stocks & Shares ISA
- Trading 212 and InvestEngine — both £0 platform fee
- Freetrade from £4.99/month for ISA access
- See full breakdown: Cheapest ISA platforms
Quick Answers
Best ISA platform for beginners UK: Trading 212 is the most accessible starting point — zero platform fee, zero commission, and fractional shares from £1. For beginners who specifically want ETF-only investing at the lowest possible cost, InvestEngine is the stronger choice.
Cheapest Stocks and Shares ISA: Trading 212 and InvestEngine both charge £0 platform fee. For full-service platforms with a flat monthly fee, Interactive Investor at £11.99/month becomes very competitive for portfolios above £50,000. See our full cheapest ISA platforms guide.
Best ISA for large portfolios: Interactive Investor's flat fee structure means larger portfolios pay proportionally less than they would on percentage-fee platforms like Hargreaves Lansdown or AJ Bell. Trading 212 remains cheaper on platform fees alone at any size.
Best app-based ISA: Trading 212 has one of the strongest mobile ISA experiences available in the UK, with a clean interface, portfolio tracking, and fractional shares. Freetrade is another mobile-first option with ISA access from £4.99/month.
Popular ISA Platform Comparisons
Comparing two specific platforms? These head-to-head comparisons break down fees, investment choice, and which platform wins at different portfolio sizes.
Trading 212 vs Interactive Investor
Zero fees vs flat monthly fee — which wins at your portfolio size, and when does II become cheaper?
Interactive Investor vs AJ Bell
Flat fee vs percentage fee — the key comparison for investors with larger portfolios and broader fund needs.
Cheapest ISA Platforms UK
Full fee breakdown across all major platforms at £5k, £25k, £50k, £100k and £250k portfolio sizes.
Best ISA for Beginners
Platform recommendations for first-time ISA investors — focused on simplicity, low minimum deposits and ease of use.