Investment Fees: The Quiet 1% That Costs You More Than Any Bad Stock Pick
Small-looking annual fees compound against you for decades, and 'free' trading apps make money from you in ways that never appear on a statement.
By Firoz Khan|18 June 2026|Updated 20 September 2026|7 min read
A fee that looks small enough to ignore, 0.5%, 1%, sometimes more, is usually the single biggest drag on your long-term returns, bigger than almost any individual investment decision you'll make. Platforms and fund managers present these fees as trivial percentages precisely because they don't feel painful in any single year. Compounded over decades, they are. Here's how the different layers of investment fees actually work, what they cost you over time with real numbers, and how 'free' trading apps make money from you in ways that never show up on a fee statement.
The three layers of fees you're actually paying
Most people think of investment costs as one number, but there are usually three separate charges stacking on top of each other. The platform fee is what your broker or investment platform charges to hold your account, often a percentage of assets or a flat monthly fee. The fund OCF (ongoing charges figure) is what the fund itself charges to run, covering the manager's costs, research, and administration, deducted directly from the fund's value before you ever see it. And transaction costs are the often-invisible costs of the fund buying and selling underlying assets, sometimes disclosed separately as a 'transaction cost' figure, sometimes folded into spreads you never see itemised at all. A platform advertising a '0.25% fee' may only be quoting the first of these three layers.
A worked example: 1% vs 0.2% total fees over 20 years
Invest £20,000 as a lump sum, assume a 7% gross annual return before fees in both scenarios (an assumption used purely to isolate the cost effect, not a return promise), and compare a combined platform-plus-fund fee of 0.2% against 1%. After 20 years at 0.2%, you'd have roughly £75,900. At 1%, roughly £63,700. The difference, just over £12,000, comes entirely from an 0.8 percentage point annual fee gap on the same underlying investment performance. Extend the same comparison to a 30-year pension timeframe and the gap widens further, often exceeding £30,000 on a moderate contribution pattern, purely from fee drag compounding year after year while your balance grows.
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Why the fee gap grows faster than it looks
Fees aren't charged on your original contribution, they're charged on your total balance each year, which means as your pot grows, the pounds lost to a 1% fee grow with it. In year one, a 1% fee on £20,000 costs £200. By year 20, if that pot has grown to roughly £77,000 before fees are deducted, that same 1% fee costs £770 in that single year alone. The fee doesn't just take a fixed bite, it takes a growing bite of a growing pie, which is exactly why a seemingly small percentage difference produces such a large pound difference over long periods.
Platform fee structures: percentage vs flat fee
Percentage-based platform fees, common for smaller portfolios, charge you a proportion of your total holdings each year, say 0.25% to 0.45%. This works out cheap when your pot is small but becomes expensive as it grows, a 0.35% fee on a £200,000 portfolio is £700 a year regardless of how little admin work that actually requires from the platform. Flat fee platforms charge a fixed amount, say £10 to £15 a month, regardless of portfolio size, which is worse value on a small pot but considerably cheaper once your holdings grow past roughly £50,000-£80,000, the exact crossover point depends on the specific platforms being compared. Larger portfolios in particular benefit from actively checking whether a flat fee structure would now cost less than the percentage fee they may have started on.
How 'free' trading apps actually make money
Several popular trading apps advertise commission-free trading, and it's true you often don't pay a visible fee per trade. That doesn't mean the app is free to run, it means the cost is hidden elsewhere. Payment for order flow is one mechanism: the app routes your trade order to a specific market maker who pays the platform for the privilege, and that market maker typically recovers the cost by giving you a very slightly worse execution price than you'd get elsewhere, a cost that never appears on your statement. FX spreads are another: converting your pounds to buy US-listed shares often carries a currency conversion margin of 0.5% to 1.5%, charged quietly within the exchange rate rather than as a separate line item. Interest on uninvested cash sitting in your account is a third: the platform earns interest on your idle balance and keeps some or all of it rather than passing the full rate to you.
Where people get this wrong
The mistake isn't paying any fee, every platform and fund needs to charge something to operate, it's assuming the headline number is the complete picture. Checking only the platform fee while ignoring the fund's OCF, or choosing a 'free' app without asking how it actually generates revenue, means the real cost stays hidden until you calculate it properly. Before committing to a platform or fund, add up every layer, platform fee, fund OCF, transaction costs, and any FX or spread costs, and run the total against your expected balance over 10 or 20 years. The difference between a well-chosen low-cost setup and a mediocre one is rarely dramatic in any single year and rarely small over a couple of decades.
A reminder
The FCA risk warning still applies to higher-risk crypto content. Always assess how much risk you are willing to take before buying.
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