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