King Charles will this week reveal how much tax he pays – as Buckingham Palace bows to pressure to be more transparent about royal finances.

The King will detail how much personal tax he paid last year on his multi-million pound income – and will pledge to continue making his tax bill public each year.

The monarch has voluntarily paid income tax and capital gains tax since Queen Elizabeth began doing so in 1993. But the total amount has been kept secret.

His son William, the Prince of Wales, has resisted calls to divulge how much tax he pays on the more than £20million he receives from the Duchy of Cornwall – the £1billion property, investments and land portfolio he took control of when he became heir to the throne. A recent estimate put the figure at up to £7million.

As Prince of Wales, Charles voluntarily declared an income tax payment of £5.9million in the 2021/22 financial year.

The King receives an income via the Duchy of Lancaster estate, which includes thousands of landholdings and properties.

The duchy last year made £27.4million for the King. He pays the highest rate of income tax after deducting official expenses. He has also paid capital gains tax on the sale of any private assets since September 2022.

The duchies, which are exempt from corporation tax, have come under scrutiny. One deal saw Guy's and St Thomas' NHS hospital trust in London pay £11.4million to store ambulances in a warehouse owned by the Duchy of Lancaster.

And earlier this year it emerged that William has received millions of pounds from the Duchy of Cornwall's leasing of HMP Dartmoor – a category C jail in Devon that has been empty since July 2024 due to high levels of a toxic gas.

The MoS understands that Thursday's declaration will reveal the amount of 'personal tax' Charles paid in 2024/25 but not show individual totals for income tax and capital gains tax.

It follows revelations that for years the former Prince Andrew paid a peppercorn rent on Royal Lodge at the Windsor Great Estate.

Ingrid Seward, a royal author and the editor-in-chief of Majesty Magazine, said: 'Andrew opened Pandora's Box – that is why journalists started going through the rents that Crown received and paid.

'I think the King wants to be seen as the monarch for transparency.'

Norman Baker, a former Government minister and expert in royal finances, said: 'We need to know why the monarch is costing £500million a year, why has he got so many houses and what's he going to do to slim down the cost of the monarchy.'

A recent poll by The Mail on Sunday found that 54 per cent of people want Prince William to be more transparent about where his income comes from and how it is spent.

The Royal Family also receives money from the Sovereign Grant, which stands at £137.9million – up from £132.1million in 2025/6.

Current legislation prevents the grant from being cut but Labour has pledged to introduce a Sovereign Grant Bill, which will allow next year's grant – and future grants – to be reduced.

Although under no legal obligation to do so, Queen Elizabeth started paying tax in the wake of the fire at Windsor Castle, which sparked a debate about how much the public should pay for the £36.5million restoration.

A laudable first step but more is needed to regain public trust 

By ANDREW LOWNIE 

The news that King Charles has agreed to disclose his personal income tax is a sign that the message is finally getting through: for far too long, the Royals have cloaked their financial affairs in secrecy – and the public has had enough.

This is not just a welcome step but a significant one. While he has hardly 'opened up the Windsor books' to public scrutiny, Charles is the first monarch in history to have gone this far. By royal standards, this makes him a moderniser and it could prove to be a marker in the monarchy's gradual acceptance that its survival increasingly depends on its accountability.

Remember, too, that this gesture by the King has not been matched by his elder son, William, the current Prince of Wales.

When Charles was Prince of Wales – before the death of Queen Elizabeth in 2022 – he published the amount of tax he'd paid on his Duchy of Cornwall income. Yet, so far, William has refused.

The Palace is certainly making the right noises, promising in last night's announcement to 'encourage wider understanding of our accountability', for example, and to 'enhance this transparency further'. It will 'continue to modernise and evolve'.

Yet even this new sign of openness fails to present anything like the full picture when it comes to the King's tax affairs.

Yes, we will be given a figure for Charles's total tax payment for the financial year 2024-2025, but not how that sum is calculated.

How much is income tax and how much capital gains tax? We will not be told. What expenses have been deducted to arrive at that figure? Silence covers that question and many more besides.

The special privileges enjoyed by the ruthlessly commercial Duchies of Lancaster and Cornwall – the multi-million-pound estates that fund the private expenditure of the King and the Prince of Wales respectively – have come under particular scrutiny.

Why are these vastly lucrative businesses – which funnel more than £20million a year into the pockets of Charles and William – exempt from some taxes?

Why, for that matter, are royal wills sealed, preventing us from seeing what is passed down to whom? What is the true scale of the Windsors' wealth and how did they acquire it?

There was a time when such questions were verboten, but no longer.

And MPs are turning up the heat. The Public Accounts Committee has announced an inquiry into the Crown Estate and the use of royal residences.

Yet this is an opportunity also. As former minister Norman Baker and I pointed out in a recent article for the Daily Mail, the Royal Family now has a chance to make itself truly accountable – and save itself in the process. Only then will it regain the trust and respect of the public and restore some moral authority after the scandals of recent years.

Let's hope this is a 'MeToo' moment for the Windsors and that they really will 'continue to modernise and evolve'.

If they have nothing to hide, they have nothing to fear.

Andrew Lownie is author of Entitled, a bestselling biography of Andrew Mountbatten-Windsor and Sarah Ferguson.