A standard adult passport renewal costs a minimum of £72.50 per person – around the price of return flights from the UK to Iceland.
Applications can cost travellers even more if they're made through a post office.
HM Passport Office gives the surplus money it raises to the Treasury after it has covered its costs.
The passport office's chief executive also told MPs that his organisation could cut fees to customers if it made a bigger surplus, but would not commit to doing so. Fee cuts were "one of the options that would then be available to us" in the event of a large surplus, he said.