The Prince of Wales is due to publish his financial accounts.
The figures will give details of his income and expenditure, including his carbon footprint, funds from the Duchy of Cornwall - the landed estate given to the heir to the throne - and tax bill.
The accounts cover the 2008/09 financial year and are expected to show Charles's private income from the Duchy is virtually unchanged, compared to the previous 12 months, despite the recession.
During 2007/08 the Prince's private income rose by 7% to £16,273,000, an increase of just over £1 million.
The cost of the Prince's official travel by air and rail will be included in the figures being released.
Last year's accounts showed that the bill for these flights and train journeys fell 22% from £1.4 million to £1.1 million on the previous financial year.
The journeys by plane and train are paid for by the taxpayer through grants-in-aid.
The amount of carbon dioxide produced by Charles's household during 2007/08 fell by 18%, or 630 tonnes to 2,795.
