King Charles has paid a £12.9 million tax bill, but is the royal tax system really fair? In this episode of Mark and Pete, we examine the King’s personal tax payment, royal finances, the Duchy of Lancaster, the Sovereign Grant and the rather peculiar constitutional arrangement whereby the monarch pays tax voluntarily, rather than because HMRC has sent a brown envelope marked, in effect, “Your Majesty, kindly cough up.”

King Charles reportedly paid £12.9 million in personal tax for 2024–25, up from £11.7 million the previous year, placing him among Britain’s largest individual taxpayers. On the face of it, that is an enormous contribution. Most of us would consider it a fairly robust tax bill, possibly requiring a sit-down and a restorative biscuit. Yet the monarch is not legally required to pay income tax or capital gains tax. The payment is voluntary, following arrangements introduced by Queen Elizabeth II in 1993.

So is this admirable royal transparency, or does it merely expose how unusual the monarchy’s financial privileges remain?

We look at the Duchy of Lancaster, the historic estate that provides the King with private income, and ask how royal earnings differ from the publicly funded Sovereign Grant. We also examine the cost of maintaining royal palaces, the refurbishment of Buckingham Palace, royal engagements, official duties and the argument that the monarchy provides Britain with tourism, diplomacy, continuity and national identity.

But there are awkward questions. The published tax figure does not reveal King Charles’s entire income, total wealth or effective tax rate. Nor does it show exactly what deductions were made for official expenditure. We know the size of the cheque, then, but not the whole calculation behind it. Transparency has opened the curtains, though perhaps not yet the windows.

Should the King be taxed under exactly the same laws as every other citizen? Is voluntary taxation sufficient in a modern democracy? Does the monarchy cost Britain too much, or does it deliver value that cannot be measured simply in pounds and pence?

Mark and Pete discuss King Charles’s £12.9 million tax bill, royal wealth, constitutional privilege, public funding, fairness and whether the Crown has genuinely rendered unto Caesar, despite being Caesar’s nearest surviving British relative.