The accounts also show the King paid £11.7m in tax for 2023-24, while Prince William paid £8.34m for the same period.

The publication of how much tax the King and Prince William voluntarily pay was a personal decision made by both men, according to their offices.

Buckingham Palace described the move as increasing transparency and aimed to "encourage wider understanding of our accountability."

Since the King became monarch and William the Prince of Wales, the combined tax bill of father and son paid to HM Revenue and Customs has been more than £50m.

The new figures do not give any detailed breakdown of how the tax has been calculated.

The King receives an annual income from his Duchy of Lancaster estate set up to give the monarch an independent source of money for official and private expenditure.

It is a portfolio of land, investments and properties. It provides the King with an annual income which in 2025-26 was £25.2m.

Other sources of income, liable for tax, include the King's own investments and savings alongside money generated by his private estates, Balmoral and Sandringham.

Initially, the Prince William did not release his tax payments when he became heir to the throne - but in line with his father, he has now made his payment of income and capital gains tax public.

Prince William receives an income from the Duchy of Cornwall - a billion-pound 130,000 acre hereditary estate which also includes the Oval cricket ground in London - which funds official duties, his office and private family life.

"Prince William pays income tax at the highest rate on any net surplus after those costs have been met. Those costs are independently audited to ensure that any deductions are appropriate," said the prince's private secretary Ian Patrick.

"The prince recognises the interest in these arrangements and the importance of appropriate transparency."

The tax payable for 2025-2026 is still being audited and will be made public next year.

The income or any detail on private investments for both the King and Prince William has not been disclosed.

Prince William has also announced he will no longer personally benefit from the £1.5m annual rent generated by the abandoned Dartmoor Prison.

He has asked for the sum to be removed from the income of the Duchy Of Cornwall with the money instead spent on supporting the local community particularly in the rural community of Princetown close to the prison.

Dartmoor has been empty since 2024 due to high levels of the toxic gas, radon, discovered within the building.

The publication of the annual royal accounts also reveal:

Meanwhile, under a new formula for calculating the Sovereign Grant, the Royal Household will receive £99.9m a year from 2027-2028. Three years ago the figure was £51.8m.

The grant covers costs such as staff, the upkeep of buildings and travel on official engagements.

The higher figure was decided upon by Royal Trustees - Prime Minister Sir Keir Starmer, Chancellor Rachel Reeves and the King's keeper of the Privy Purse and treasurer James Chalmers.

The extra money will be used pay for the upkeep of historic buildings, strengthen cyber security at royal residences and support the transition to green energy with £11m earmarked to replace boilers at Windsor Castle.

Chalmers insisted the funding was "not a blank cheque" and there were strict checks to ensure the grant was value for money.

"Expenditure is governed by the same standards and disciplines as any publicly funded body, with strict value-for-money requirements, detailed planning, multi-year strategies, independent audit, and Treasury oversight," he said.

For the past 10 years, the Sovereign Grant has been at a higher level than its core sum to cover the costs of the major refurbishment of Buckingham Palace which will be complete by the end of 2027.

With the work finished, the annual figure will fall from £137.9m to a core funding of £99.9m - a sum that will be unchanged for the next five years when it will next be reviewed but is significantly higher than previous years.

"It is important to emphasise that the Sovereign Grant does not provide personal income to members of the Royal Family," Chalmers said. "It funds the work of the institution – not private lives or private wealth."