Choosing the right investment platform matters more than most investors realise — not because one platform magically delivers better returns, but because fees compound over decades, and a platform that is frustrating to use leads to inaction and worse outcomes. A platform charging 0.5% more per year than a competitor costs a typical investor tens of thousands of pounds over 20–30 years.
This hub covers how UK investment platforms work, how to compare fee models, which platforms suit different investor types, what FSCS protection means, and how to hold your ISA and pension on the same platform. For what to invest in, use the Index Funds and ETFs hub.
FSCS Protection and Account Safety
Before comparing fees, understand the protection framework:
| What is protected | FSCS limit | Notes |
|---|---|---|
| Investments (shares, funds, ETFs) | Up to £85,000 | Only if platform misappropriates assets |
| Cash held uninvested on platform | Up to £85,000 | Per firm, same as banking |
| Cash ISA | Up to £85,000 | Per firm |
Investment assets held in a nominee account legally belong to you, not the platform. If the platform goes bust, a FSCS claim would only arise if the platform had misappropriated your assets — not simply for market losses. The £85,000 FSCS limit applies to the claim value, not the number of investments.
Fee Model Comparison: Percentage vs Flat Fee
| Portfolio size | Percentage fee (0.25%/year) | Flat fee (£10/month = £120/year) | Verdict |
|---|---|---|---|
| £10,000 | £25/year | £120/year | Percentage wins |
| £30,000 | £75/year | £120/year | Percentage wins |
| £48,000 | £120/year | £120/year | Break-even |
| £100,000 | £250/year | £120/year | Flat fee wins |
| £250,000 | £625/year | £120/year | Flat fee wins by far |
As portfolios grow, flat-fee platforms become significantly more cost-effective. If you are starting small but expect to accumulate over £50,000–£100,000, choose a platform with a fee structure that scales well.
Platform Comparison by Investor Type
| Investor type | Platform fee model | Good examples | Watch-out |
|---|---|---|---|
| Beginner, monthly index fund investing | Low-cost percentage | Vanguard (0.15%), InvestEngine (0% DIY) | Limited fund range |
| Active investor, wider fund range | Medium percentage | AJ Bell (0.25%), Fidelity (0.35% capped) | Rises steeply for shares |
| Large portfolio passive investor | Flat fee | Interactive Investor (from £4.99/month), iWeb (one-off fee) | Higher proportional cost on small pots |
| Wants automatic management | Robo-advisor (0.25–0.75%) | Nutmeg, Moneyfarm, Vanguard Managed | Extra layer of cost vs DIY |
| App-first, commission-free trading | Free share trading | Trading 212, Freetrade | Revenue model is FX spreads and premium tiers |
Worked Example: Platform Fees on a Growing Portfolio
Scenario: Emma invests £500/month and grows her ISA to £200,000 over 15 years. Platform fee comparison:
| Platform model | Annual fee at £200,000 | Over 15 years (cumulative) |
|---|---|---|
| 0.15% percentage | £300/year | ~£17,000 total fees |
| 0.45% percentage | £900/year | ~£51,000 total fees |
| Flat £10/month | £120/year | ~£6,800 total fees |
The difference between a 0.45% platform and a flat £10/month platform on a £200,000 portfolio is over £44,000 in cumulative fees — money that would otherwise compound inside Emma’s ISA.
Account Types Available on Major Platforms
Most full platforms offer:
| Account type | Tax treatment | Annual limit |
|---|---|---|
| Stocks and Shares ISA | Tax-free gains and dividends | £20,000 |
| Cash ISA | Tax-free interest | £20,000 (shared with S&S ISA) |
| Lifetime ISA | 25% government bonus + tax-free | £4,000 (counts in £20,000 ISA limit) |
| Junior ISA | Tax-free for child | £9,000 |
| SIPP | Tax relief on contributions, tax-free growth | £60,000 (annual allowance) |
| General Investment Account | Taxable — CGT and dividend tax apply | Unlimited |
DIY vs Robo-Advisor: The Key Trade-Off
| DIY platform | Robo-advisor | |
|---|---|---|
| Who makes investment decisions? | You | Automated (based on risk profile) |
| Annual cost (total) | Fund: 0.10–0.20% + Platform: 0.0–0.45% | Fund + platform + management: 0.35–0.95% |
| Rebalancing | Manual (or platform tools) | Automatic |
| Minimum investment | Often £1 | Usually £500–£5,000 |
| Best for | Confident investors who want control | Beginners who want a managed solution |
The extra cost of a robo-advisor (often 0.3–0.5% more per year than DIY) is significant over time but buys automatic rebalancing and removal of decision-making anxiety.
Related Hubs
- Index Funds and ETFs hub — what to invest in on your platform
- ISAs hub — ISA types, allowances, and rules
- SIPP hub — holding a pension on an investment platform
The Investment Platforms Cluster
- Best Investment Platforms UK
- Best Investment Platform for Beginners
- Vanguard Investor Review
- Hargreaves Lansdown Review
- AJ Bell Review
- Interactive Investor Review
- Trading 212 Review
- Freetrade Review
- Robo-Advisors Compared UK
How to Review Your Platform Choice
Most people choose a platform once and never revisit it. But your needs change as your portfolio grows:
- At £0–£25,000: prioritise low cost, simplicity, and ISA availability; a percentage-fee platform or robo-advisor is usually fine
- At £25,000–£75,000: check whether a flat-fee platform has become cheaper; start comparing total annual costs
- At £75,000+: flat-fee platforms almost always win on cost; switching is worth the one-time administration effort
- Holding SIPP and ISA: see whether consolidating onto one platform saves administration without sacrificing cost or quality
Switching platforms (known as an in-specie transfer for investments, or a cash transfer) typically takes 2–6 weeks and should not trigger a tax event inside an ISA or SIPP.