The Prince of Wales's funding from the taxpayer rose by almost a quarter last year, Clarence House accounts show.
The money from grants-in-aid and Government departments jumped 23.5% from £2,454,000 to £3,033,000.
The main cost was a 48% rise in official travel by air and rail which increased from £1,157,000 to £1,710,000.
Charles's private income increased by just 1% to £16.4 million during the last financial year.
The money which comes from the surplus generated by the Duchy of Cornwall - the landed estate given to the heir to the throne - increased by £185,000 to £16,458,000.
His official expenditure rose by nearly 20% from £10,451,000 to £12,513,000.
The heir to the throne paid less tax, with his bill falling from £3,429,000 to £3,093,000 - a drop of almost 10%.
