Accounts released by the prince’s Clarence House office show that Charles spent £1.08 million (€1.2m) on air and rail travel in 2010-2011, a rise of 56% from the previous year.
His income from the taxpayer, referred to as grants in aid and government income, also rose by 17% to £1.96m, the accounts show, while his tax bill was up from £3.5m to £4.4m.
The prince’s principal private secretary, Michael Peat, said the figures had been affected by the wedding of Charles’s son William to Kate Middleton in April.
He also defended the rise in travel costs and an increase in the number of staff, saying staffing costs had only risen by 1% as many extra employees had been temporary.
The latest figures had also been skewed by comparison with the low spending of the previous year.
“The costs have gone up because we didn’t pay for Canada last year,” the Daily Telegraph quoted Peat as saying.
“It’s all skewed by the fact that the longest journey in 2009-2010 was to Canada and the Canadians paid for it.”
However, anti-monarchist group Republic said it would be writing to the parliament’s public accounts committee to ask them to launch an inquiry.
“Charles’s spending is spiralling out of control. Why on earth are taxpayers continuing to fund his lavish lifestyle when public services are being cut,” Republic spokesman Graham Smith said.