Choosing the best Stocks & Shares ISA in the UK isn’t just about finding the lowest fees — it depends on how you invest, what you invest in, and the size of your portfolio.
Some platforms offer the lowest costs for ETF investors, while others provide better value for traditional funds or larger portfolios.
If you’re primarily focused on minimising fees, see our guide to the cheapest Stocks & Shares ISA in the UK.
If you’re new to investing, see our guide to the best Stocks & Shares ISA for beginners in the UK.
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Best ISA platforms · Best ISA by category · Cheapest vs best · How to choose an ISA · FAQs
Quick Verdict
- Best overall ISA: Vanguard Investor (simple, low-cost, long-term investing)
- Best for beginners: Vanguard Investor
- Best for ETFs: Trading 212 / InvestEngine
- Best for large portfolios: Interactive Investor
- Best low-cost option: See our full cheapest ISA comparison
What is the Best Stocks & Shares ISA?
There is no single “best” Stocks & Shares ISA — the right choice depends on:
- The size of your portfolio
- Whether you invest in ETFs or funds
- How frequently you invest
For example, ETF-focused platforms can offer extremely low costs, while traditional platforms may provide a wider range of funds and research tools.
If you’re unsure whether ETFs or funds are right for you, see our guide on ETF vs OEIC investing.
The table below compares some of the best Stocks & Shares ISA platforms based on cost, features and suitability.
Best Stocks & Shares ISA Platforms (2026)
| Platform | Best for | Example cost (£50k) | Key features | Verdict |
|---|---|---|---|---|
| Vanguard | Simplicity & low-cost investing | ~£190 | Low-cost funds, simple platform | Best overall |
| AJ Bell | Balanced cost & flexibility | ~£240 | Wide investment range | Strong all-rounder |
| Fidelity | Fund investing | ~£290 | Free fund dealing | Good for funds |
| Hargreaves Lansdown | Research & tools | ~£290 | Strong platform features | Premium option |
| Interactive Investor | Large portfolios | ~£187 | Flat monthly fee | Best for scale |
| Trading 212 | ETFs | ~£110 | No platform fee | Cheapest ETFs |
| InvestEngine | ETFs | ~£110 | No platform fee | Low-cost ETFs |
| IG | ETFs | ~£110 | No platform fee, share and ETF access | Strong ETF option |
For a full cost breakdown, see the cheapest ISA comparison.
Best ISA by Category
Best Overall ISA
Vanguard Investor
Vanguard offers a simple, low-cost platform focused on long-term investing. Its platform fee is relatively low and capped annually, making it suitable for a wide range of investors.
Best ISA for Beginners
Vanguard Investor
For new investors, simplicity matters. Vanguard’s platform is easy to use, with a clear range of funds and ETFs, making it a strong starting point.
Best ISA for ETFs
Trading 212 / InvestEngine / IG
Platforms such as Trading 212, InvestEngine and IG can be highly cost-effective for ETF investors because they do not charge a traditional platform fee in the same way as many mainstream providers.
However, they do not support traditional mutual funds, so they are best suited to investors building ETF-only portfolios.
For more detail, see our ETF vs OEIC comparison.
Best ISA for Low Costs
If your priority is minimising fees, ETF-focused platforms often come out cheapest.
See the full breakdown in our cheapest Stocks & Shares ISA guide.
Best ISA for Large Portfolios
Interactive Investor
Flat-fee platforms become more competitive as portfolio size increases. Interactive Investor’s fixed monthly fee can offer better value at higher balances compared to percentage-based platforms.
Cheapest vs Best — What’s the Difference?
The cheapest platform is not always the best.
Low-cost platforms may:
- offer fewer investment options
- lack research tools
- be limited to ETFs
Meanwhile, higher-cost platforms may provide:
- broader investment choice
- better tools
- additional account types
If cost is your main concern, see our full cheapest ISA comparison for a detailed cost breakdown across platforms.
How to Choose the Right ISA Platform
When choosing a Stocks & Shares ISA, consider:
- Portfolio size: percentage fees vs flat fees
- Investment type: ETFs vs funds
- Fees: platform, dealing, and fund costs
- Frequency: regular investing vs lump sum
The right platform depends on how these factors combine for your situation.
Platform Comparison Summary
- Vanguard: best for simple, low-cost investing
- AJ Bell / Fidelity: balanced platforms for funds
- Interactive Investor: strong for larger portfolios
- Trading 212 / InvestEngine / IG: strong low-cost options for ETF investors
Final Thoughts
The best Stocks & Shares ISA depends on how you invest.
ETF-only platforms can offer very low costs, while traditional platforms provide a broader investment range and additional features.
For many investors, the decision comes down to balancing cost, flexibility, and simplicity.
FAQs
What is the best Stocks & Shares ISA in the UK?
There is no single best ISA. Platforms like Vanguard, AJ Bell and Interactive Investor are popular depending on your investment style and portfolio size.
Is Vanguard the best ISA?
Vanguard is often considered one of the best options for simple, low-cost investing, particularly for long-term investors.
What is the cheapest ISA platform?
ETF-focused platforms such as Trading 212, InvestEngine and IG are often the cheapest due to zero platform fees.
See the full cheapest ISA comparison.
Should I choose ETFs or funds?
ETFs often have lower costs, while funds can offer simplicity and regular investing options.
See our ETF vs OEIC guide.