What 0.6% Costs Over Thirty Years

Fund fees are quoted annually, which is what makes them easy to dismiss. 0.75% against 0.12% reads as a rounding error on a £20,000 balance — about £126 a year. Over thirty years of contributions it is not a rounding error.

The arithmetic

Annual charge	Balance at 30 yrs	Paid in fees
0.12%	£487,000	£11,400
0.40%	£455,000	£36,900
0.75%	£418,000	£67,200
1.20%	£374,000	£102,800

Assumptions, stated plainly: £500 a month, 6% nominal growth before charges, charges deducted monthly, no contribution increases, and no tax. Change the growth rate and every number moves; the ordering does not. The gap between the top and bottom row is roughly two and a half years of contributions.

Four curves that look identical for a decade and then separate: the fee drag is invisible exactly when it matters most to fix.

Where the fee hides

Platform charge — often 0.25–0.45%, separate from the fund. Some cap it in cash terms, which favours larger balances.
Fund OCF — the headline number, and the one worth comparing.
Transaction costs — disclosed separately and frequently omitted from comparisons entirely.
Adviser charge — 0.5% ongoing is common and is sometimes worth it, but it must be counted.

Add the three layers before comparing anything. A cheap fund on an expensive platform is not a cheap arrangement.

The part that is not about fees

Fees are worth optimising once, then leaving alone. Contribution rate does more: raising £500 a month to £560 beats the entire 0.75%-to-0.12% saving in the table above. This is not investment advice and your circumstances will differ — but the two levers, in order of size, are how much goes in and what comes off the top.