Why Fees Destroy Your Returns

Of all the things that affect how much your investments grow over time, fees are one of the most damaging, and the least talked about. A small percentage number on a fund factsheet sounds entirely harmless. What it does to your wealth over 30 years is not.

This page puts real numbers on it. By the end, you’ll understand why choosing a low-cost fund over a high-cost one is one of the most important investing decisions you can make.

How Investment Fees Work

When you invest in a fund, whether an index fund or an actively managed one, you pay an annual fee for the fund to be managed. This is usually expressed as the Ongoing Charge Figure, or OCF (sometimes called the Total Expense Ratio, or TER). It’s deducted automatically from the fund’s value, so you never write a cheque or see it leave your account. It just quietly reduces your returns every year.

What 1% looks like You invest £10,000 in a fund with a 1% annual fee. In a year where the market returns 7%, your fund returns 6% after the fee is deducted. That’s £60 lost in year one. Not dramatic. But the fee compounds against you every year, on a growing pot of money. By year 30, that single percentage point has cost you an enormous amount.

The Real Cost Over Time

Let’s compare two investors. Both invest £500 per month for 30 years. Both achieve the same underlying market return of 7% per year. The only difference is the fund they choose.

Annual Fee	Total Invested	Final Portfolio	Lost to Fees vs 0.10%
0.10% (typical index fund)	£180,000	£585,000	£585,000
0.50% (low-cost active)	£180,000	£528,000	-£57,000
1.00% (average active fund)	£180,000	£476,000	-£109,000
1.50% (expensive active fund)	£180,000	£429,000	-£156,000
2.00% (high-cost fund + adviser)	£180,000	£388,000	-£197,000

Paying 1% more in annual fees than necessary, just 1%, costs this investor £109,000 over 30 years. That’s more than half their total contributions wiped out by a fee that felt invisible.

The investor paying 2% ends up with £197,000 less. On the same money. With the same market returns. The only variable is the fee.

Why Fees Compound Against You

The reason the numbers are so dramatic is the same reason compound interest is so powerful in your favour, only here it works against you.

The fee isn’t applied to your original investment each year. It’s applied to your entire growing pot. As your portfolio gets larger, the same percentage fee takes a larger absolute amount. By year 25, that 1% annual fee on a large portfolio is taking thousands of pounds a year, money that would otherwise have been compounding for you.

The compounding cost, visualised simply Year 1: 1% fee on £6,000 portfolio = £60 lost Year 10: 1% fee on £83,000 portfolio = £830 lost Year 20: 1% fee on £245,000 portfolio = £2,450 lost Year 30: 1% fee on £560,000 portfolio = £5,600 lost, in that single year alone  The fee isn’t just taking money. It’s taking money that would have grown.

Active Funds vs Index Funds on Fees

Actively managed funds, where a team of analysts and fund managers pick stocks trying to beat the market, typically charge between 0.75% and 1.5% per year. Some charge more.

Index funds, which simply track a market index with minimal human involvement, typically charge between 0.05% and 0.25% per year.

For those higher fees to be justified, an active fund needs to outperform the index by enough to cover the fee difference, every year, consistently. As we discussed in our page on index funds, the evidence shows that around 85-90% of active funds fail to do this over 15 years.

So the typical active fund investor is paying significantly more and getting less in return. Not because the fund managers are bad at their jobs. Because markets are efficient enough that consistent outperformance after costs is genuinely rare.

Fund Type	Cost & Context
Typical index fund	OCF: 0.10 – 0.25%, Tracks a market index. No stock picking. Low cost by design.
Low-cost active fund	OCF: 0.40 – 0.75%, Human-managed stock selection. Some perform well, most don’t beat index over time.
Average active fund	OCF: 0.75 – 1.25%, Traditional managed fund. High ongoing cost significantly reduces long-term returns.
Expensive active fund	OCF: 1.25 – 2.00%+, Very difficult to justify after fees. Needs exceptional performance just to match the index.

Other Fees to Watch Out For

The fund’s OCF is the main fee, but it’s not always the only one. Here are the others worth understanding:

Platform fees

The platform you use to hold your investments usually charges a fee for their service, either as a percentage of your portfolio or a flat monthly fee. For smaller portfolios, a percentage fee (e.g. 0.15-0.45% per year) is usually cheapest. For larger portfolios, a flat fee often works out better. Platform comparison matters.

Trading charges

Some platforms charge a fee each time you buy or sell a fund. If you’re investing a regular small amount every month, a platform that charges £10 per trade is very expensive relative to your investment. Look for platforms that offer free regular investing.

Entry and exit fees

Some older or more complex products still charge fees to enter or leave a fund. Modern index funds and ETFs typically don’t. Avoid any fund that charges these without a very clear reason.

Adviser fees

If you use a financial adviser, their fee, typically 0.5-1% of your portfolio per year, adds to your total cost. Advice can absolutely be worth paying for in the right circumstances, but it’s important to factor this into your total annual cost and understand what you’re getting for it.

How to Keep Your Fees as Low as Possible

• Choose index funds with an OCF below 0.25%, global index funds typically achieve this easily
• Pick a platform with a fee structure that suits your portfolio size, compare before you commit
• Use a platform that offers free regular investing so monthly direct debits don’t generate trade fees
• Avoid funds with entry or exit charges
• Review your total annual cost periodically, OCF plus platform fee plus any trading costs
• Don’t switch funds or platforms unnecessarily, trading costs and switching friction can undo the savings

A useful benchmark A well-constructed, low-cost portfolio for a UK investor should have a total annual cost, fund OCF plus platform fee, of around 0.20 to 0.45%. If you’re paying more than 0.75% in total, it’s worth understanding why and whether it’s justified.

Fees are certain, returns are not Investment returns vary year to year and cannot be guaranteed. Fees, however, are taken regardless of how your investments perform. In a year where the market is flat, a 1.5% fee still costs you 1.5% of your portfolio. This makes minimising fees one of the only genuinely reliable ways to improve your long-term outcome.

Not financial advice This page explains how investment fees work and their mathematical impact over time. It is not a recommendation of any specific fund or platform. Please consider your own circumstances and do your own research before investing.

What Next?

You now understand the two most fundamental concepts in long-term investing, index funds and the devastating impact of fees. The next logical step in the Fundamentals section is active vs passive investing, which looks at the evidence in more detail, or diversification, which explains how to spread risk effectively across your portfolio.