Forty per cent of your private pension pot can disappear because of fees, according to analysis by pensions expert, David Pitt-Watson.
The loss has been calculated in a report for the Royal Society for the encouragement of Arts, Manufactures and Commerce, which criticises the costs of private pension funds.
So how do seemingly small charges on your pension fund actually add up to such a big sum? Money Box reporter Ruth Alexander explained the mathematics.
And why the true impact of these charges are not made clear to the customer?
Money Box interviewed the technical director of the Pensions Advisory Service, Des Hamilton, and head of pensions policy at Standard Life, John Lawson.
This item was first broadcast on Radio 4's Money Box on Saturday, 26 September 2009.