Fees reduce the amount of money left invested, so their effect can grow over time as you miss out on potential returns on the fees paid. The overall impact depends on the charges involved, how often they apply, your investment amount, performance and holding period. Check the fund, platform or pension documents for ongoing charges, transaction costs and any other fees, and compare the total cost rather than one charge alone. Charges are only one factor, so consider risk, diversification and suitability too, and seek regulated advice if you need help assessing your options.