Accounts showed the future King spent just over £20 million in the period of 2011-12, compared with just over £19.5 million the year before. In total this was an increase of 3.6 per cent.
The extra cost has no doubt partly come from the expense of the royal wedding and the spending in the Duchess of Cambridge's first year as a royal.
Following the wedding, the office of the Duke and the Duchess of Cambridge and Prince Harry took on 1.2 extra staff members.
The cost of that and much of the expenditure for Kate's wardrobe, thought to be in the region of £35,000, would have come from a budget of £2.9 million allocated to Charles' private secretaries and the office of the three younger royals. This spending went up by £100,000.
The Diamond Jubilee also added to the costs. For example, the Prince and his wife travelled nearly 48,000 miles (77,248km) in Britain and abroad.
Charles was able to afford it, however. His income from the Duchy of Cornwall and public funding in the form of grants went up by the same percentage, from £19.76 million to £20.48 million.
The figures are revealed in The Annual Review – released each year and detailing Charles' activities.
It also reveals the couple helped raise, directly or indirectly, £131m for charity.
Expenses of the Prince of Wales 2011-2012
- Total spending - £20.23 million – up from £19.5 million
- Income from Duchy of Cornwall and Government grants - £20.48 million – up from £19.76 million
- Budget for the Prince's private secretaries' office and the office of the Duke and Duchess of Cambridge and Prince Harry - £2.9 million – an increase of £100,000
- Total cost of travel for Charles and the Duchess of Cornwall - to £1.3 million – up from £1.08 million
- Total staff - 134.9 – an increase of 2.1
- Tax bill - £4.5 million – an increase of £98,000
- Total raised for charity - £131 million