This article studies the effects on individual welfare caused by administrative charges or fees on balance (assets) and flow (contributions) during the accumulation phase of a defined-contribution (DC) pension plan under the system of individual retirement accounts (IA). Assuming a complete financial market and suitable deterministic functions to model contributions and administrative charges, we are able to contrast the optimal expected utility of terminal wealth generated under both charge schemes. In this framework, we also derive closed-form expressions to determine equivalent administrative charges, that is, the precise level of charges on flow and balance that makes them indifferent to the risk-averse participant. These expressions are independent of the market price of risk, the risky asset's volatility and the participant's utility function. Furthermore, our methodology can be helpful for regulators and policy makers aiming to dynamically track the future evolution of administrative charges or to fairly compare costs across DC pension systems, especially those operating under charge on flow.