King Charles and Prince William’s property empires are taking millions of pounds from cash-strapped charities and public services including the NHS, state schools and prisons, according to a new investigation. The reports claim the Duchies of Lancaster and Cornwall, which are exempt from business taxes and used to fund the royals’ lifestyles and philanthropic work, are set to make at least £50m from leasing land to public services. The two duchies hold a total of more than 5,400 leases. One 15-year deal will see Guy’s and St Thomas’ NHS hospital trust in London pay £11.4m to store its fleet of electric ambulances in a warehouse owned by the Duchy of Lancaster, the monarch’s 750-year-old estate. The king will also make at least £28m from windfarms because the Duchy of Lancaster retains a feudal right to charge for cables crossing the foreshore, according to an investigation by Channel 4’s Dispatches and the Sunday Times. William’s Duchy of Cornwall, the hereditary estate of the heir to the throne, has signed a £37m deal to lease Dartmoor prison for 25 years to the Ministry of Justice, which is liable for all repairs despite paying £1.5m a head for a jail empty of prisoners because of high levels of radon gas. His estate also owns Camelford House, a 1960s tower block on the banks of the Thames, which has brought in at least £22m since 2005 from rents paid by charities and other tenants. Two cancer charities, Marie Curie and Macmillan – of which the king is a longstanding patron – have both recently moved out to smaller premises. The Duchy of Cornwall has charged the Royal Navy more than £1m to build and use jetties and moor warships. It also charges the army to train on Dartmoor but the Ministry of Defence refused a Freedom of Information Act request asking how much it costs. The duchy also made more than £600,000 from the construction of a fire station and stands to get nearly £600,000 from rental agreements with six state schools. In spite of the king and Prince William’s speeches and interventions on environmental issues, many residential properties let out by the royal estates are in breach of basic government energy efficiency standards. InvestigatorsThe investigation found 14% of homes leased by the Duchy of Cornwall and 13% by the Duchy of Lancaster have an energy performance rating of F or G. Since 2020, it has been against the law for landlords to rent out properties that are rated below an E under the Minimum Energy Efficiency Standards regulations. The Duchy of Lancaster said: “Over 87% of all duchy-let properties are rated E or above. The remainder are either awaiting scheduled improvement works or are exempted under UK legislation.” The royal estates also have deals with mining and quarrying companies. The investigation has prompted calls for a parliamentary investigation and for the two empires to be folded into the crown estate, which sends its profits to the government. The king and Prince William pay income tax on profits from the estates after business expenses have been deducted, but both now refuse to say how much. Critics say the estates, the income from which have been used by successive governments to keep the headline cost of the monarchy to the taxpayer down, enjoy a commercial advantage over rivals because they are exempt from corporation tax and capital gains tax. Baroness Margaret Hodge, a former chair of the Commons public accounts committee, said the duchies should at least pay corporation tax. “This would be a brilliant time for the monarch to say, I’m going to be open, and I want to be treated as fairly as anybody,” she said. Both duchies said they were commercial operations that complied with statutory requirements to disclose information. They also emphasised their efforts to become greener. The Duchy of Lancaster said: “His majesty the king voluntarily pays tax on all income received from the duchy.”