Tax and personal expenditure amounted to £5,226,000 in 2004-2005. However that appears to be the limit of the public information. So although we are told tax is paid, their is an official veil on how much tax - a public company would be obliged to make full accounts available.
The Duchy of Cornwall, one of the oldest landed estates, is said to be worth £505 million. So an income of £13.2 million is not unreasonable. The Queen received £9.8 million from the Duchy of Lancaster, which has a capital value of £308.6 million.
But the Public Accounts Committee (a parliamentary committee) in 2005 called on the Treasury to justify why the duchies are exempt from corporation and capital gains tax. One committee member, a Labour backbencher, claimed that the Duchy of Cornwall has saved up to £40 million through its tax-free status, a figure dismissed by one of the prince's senior aides as "ludicrous" and "plucked from the air". And the committee wants the National Audit Office to be given the power to audit the accounts of both duchies, which in the past have been audited privately.
It is believed that the Prince of Wales pays income tax on the income of the Duchy of Cornwall, applying normal income tax rules and at current tax rates, and pays income tax on all other income and capital gains tax like any private individual.
Tax is calculated after deducting business expenditure, the biggest source of which is The Prince's staff .
Duchy of Cornwall Income and Expenditure