Choose an investment platform by matching its charges to how you invest: percentage fees suit smaller pots, flat fees suit larger ones. Then check it offers the accounts you need, ISA, SIPP, general account, the investments you want, sound customer service, and non-negotiably, FCA regulation and FSCS protection.
The short answer
- Charges are the biggest differentiator: percentage fees suit smaller pots, flat fees suit larger ones.
- Remember platform charges sit on top of fund charges, add both to find your true annual cost.
- Check the platform offers the accounts (ISA, SIPP, general account) and investments you actually need.
An investment platform (sometimes called a fund supermarket or investment account) is the online service that holds your investments in one place, your ISA, pension and general account, your funds and shares, all under a single login. Choosing the right one matters, because the wrong charging structure can quietly cost you thousands over a couple of decades. The good news is that the decision comes down to a handful of clear questions.
Start with the charges
Platform fees come in two broad shapes, and the better deal depends almost entirely on the size of your pot. Understanding this one distinction does most of the work:
How platform charging structures compare
| Fee type | How it works | Best suited to |
|---|---|---|
| Percentage fee | A yearly charge (often ~0.25%–0.45%) on the value of your investments, sometimes capped | Smaller and growing portfolios |
| Flat fee | A fixed monthly or annual amount regardless of pot size | Larger portfolios (tens of thousands+) |
| Dealing charges | A cost each time you buy or sell shares, ETFs or investment trusts | Frequent traders should compare carefully |
The rule of thumb: on a £10,000 pot a 0.30% percentage fee is just £30 a year, cheaper than most flat fees. But on a £250,000 pot that same percentage is £750 a year, where a flat-fee platform charging a fixed sum could save you hundreds annually. Do not forget the fund charges sit on top of the platform charge; the two together are your true cost. Our guide to investment platforms explained breaks the numbers down further.
It is easy to underestimate how much these charges compound over an investing lifetime. A difference of just half a percent a year, left to run for twenty or thirty years, can quietly cost the equivalent of several years’ worth of contributions. That is why it pays to work out your likely pot size first and let it steer the choice, rather than being drawn in by a headline “low fee” that only suits a portfolio a fraction of yours. Some platforms also cap the percentage they charge on shares and investment trusts, which can matter a great deal for larger holdings.
Then check it does what you need
Cost matters, but a cheap platform that cannot hold the account you need is a false economy. Run through this checklist before you commit:
- 1
The right accounts
Does it offer the wrappers you want, a stocks and shares ISA (£20,000 annual allowance), a SIPP for pension saving, a Junior ISA, and a general investment account for anything beyond your allowances?
- 2
The right investments
If you want low-cost index funds and ETFs, most platforms cover them. If you want individual shares, investment trusts or more specialist holdings, check they are available.
- 3
Usability and service
A clear app or website, responsive customer support, and helpful research tools make a real difference over years of use.
- 4
Transfer and exit terms
Check whether it charges to transfer investments in or out. Punitive exit fees can trap you on a platform that later stops being competitive.
Never skip this check
Only ever use a platform authorised by the Financial Conduct Authority and covered by the Financial Services Compensation Scheme (FSCS), which protects up to £85,000 per person, per firm, if the provider fails. You can verify any firm on the FCA Register in under a minute.
That FSCS protection is a genuine safety net, though it is worth understanding what it does and does not cover, we explain this in our answer on what happens if your platform goes bust. Crucially, it protects against the firm failing, not against your investments falling in value; markets can always go down as well as up.
Match the platform to your style
Finally, be honest about the kind of investor you are. A hands-off investor who buys a couple of diversified funds and holds them for decades should prioritise low percentage fees and simplicity. A more active investor trading shares and trusts should weigh dealing charges heavily. And if you are unsure which investments belong on the platform at all, that is a question about strategy rather than plumbing: our guide to how to start investing is a good next step.
A common mistake is to treat the platform decision as the whole decision. In reality the platform is just the shelf your investments sit on; what actually drives your outcome is the mix of funds you place on it and how consistently you contribute. It is worth choosing a sensible, well-regulated platform and then moving swiftly on to the questions that matter more, your asset allocation, your contributions, and your time horizon. A perfectly optimised platform holding a poorly chosen portfolio is a false victory.
If comparing platforms and building a portfolio feels daunting, you do not have to do it alone. Vetted Wealth can match you, at no cost, with an independently vetted, FCA-regulated investment adviser who can recommend a suitable platform and strategy for your circumstances. This is information, not personal advice, and investments can fall as well as rise.
In summary
- Charges are the biggest differentiator: percentage fees suit smaller pots, flat fees suit larger ones.
- Remember platform charges sit on top of fund charges, add both to find your true annual cost.
- Check the platform offers the accounts (ISA, SIPP, general account) and investments you actually need.
- Only use FCA-regulated, FSCS-protected platforms, and check for exit fees before committing.
- Match the platform to how you invest, hands-off investors and active traders have different priorities.
Sources and further reading
- Investing basics MoneyHelper
- Check the Financial Services Register Financial Conduct Authority
- Individual Savings Accounts GOV.UK
Read the full guide
For the complete picture, see our in-depth guide: Investment Platforms Explained.
Speak to a vetted investment management specialist
This is free information, not personal advice. When you’re ready, we’ll match you with an independently vetted, FCA-regulated specialist, free, and with no obligation.
