King Charles and Queen Camilla will not move into Buckingham Palace when £369m of buildings works to update it finish next year, preferring to remain at Clarence House, their London home nearby.

The announcement came as it was revealed the king paid £12.9m in income and capital gains tax in 2024-25 on his personal income, known as the privy purse, making him among the country’s top 100 taxpayers. Prince William paid £7.76m for the same period.

Palace finances also revealed that the core sovereign grant – the amount of public money given to the king to carry out official duties – had almost doubled in three years. From 2027-28 it will be £99.9m, up from £51.8m in 2024-25, after a review by the royal trustees: the UK prime minister, Keir Starmer; the chancellor, Rachel Reeves; and the king’s accountant and keeper of the privy purse, James Chalmers.

Charles and Camilla made the decision not to move to Buckingham Palace after “careful consideration and to greatly increase opportunities for public access”, and will remain at Clarence House for the duration of his reign, said Chalmers.

They would have access to private rooms at the palace to retire to during the day and for occasional overnight stays. It would continue to be the ceremonial and operational centre of royal life.

“[Buckingham Palace] is and will remain monarchy HQ, the crown jewel of our national buildings, with the sovereign’s standard flying proudly from the roof whenever his majesty is in London,” said Chalmers.

A royal spokesperson said it would be a “buzzing hive of royal activity in every other way”. “The palace will continue in every traditional way to be the beating heart of the monarchy, just not its resting head,” said the spokesperson.

Buckingham Palace has been a royal residence since the accession of Queen Victoria in 1837. It is not known if Prince William intends to move there when king.

Charles became the first monarch to publish their tax bill, with accounts revealing he paid £12.9m in income and capital gains tax on his private assets in 2024-25, and £11.7m the year before. He has paid more than £30m since his accession.

There is no legal obligation on the king, or Prince of Wales, to pay tax. But in 1993, after public outcry over proposals the public should foot the restoration bill after a fire at Windsor Castle , the late Queen Elizabeth II and Charles “volunteered” to pay tax.

The tax campaigner Dan Neidle described the limited information shared as a “sideshow”, saying there was no transparency because nothing was verifiable. He said a proper level of disclosure would involve publishing detailed accounts similar to those produced by large private companies.

“The reality is that the king is completely unlike any other taxpayer, and the boundary between personal assets and crown assets is very wobbly. So it’s far from clear he should receive the same privacy.”

Graham Smith, chief executive officer of the anti-monarchy group Republic, said: “Despite ongoing concerns about the huge cost of the royals, the grant will remain hugely inflated on its initial level of £31m in 2012. If that had risen by inflation the grant would stand at £45m, not £100m.

“The government agreed to spent £369m on refurbishing Buckingham Palace, and now Charles doesn’t want to use it. But he’ll keep it under lock and key for when he does. Clearly the palace needs to be fully open to the public all year round.”

Currently the public can access the palace in seasonal tours of its state rooms, guided access to the East Wing, and visits to the King’s Gallery and the Royal Mews.

George Foulkes, a Labour peer and former Scotland minister, said he was “deeply worried about the amount of money being spent and the lack of transparency”. He believed revealing the king’s tax payments was a “diversionary tactic to get away from the whole question of the sovereign grant”.

“What we really need is a giant committee of both houses of the Commons and the Lords to have some supervision of this expenditure. Governments, even Labour governments, are reluctant to clamp down. It’s too much of an establishment closing ranks. It does need a more radical look.”

Charles received £25.2m from the 2025-26 profits from Duchy of Lancaster – a historical portfolio of land and assets held in trust for reigning sovereigns to give them a private income.

No breakdown was given of his tax bill. Tax is only payable on the amount of the duchy surplus less official expenses, which include funding other working royals and costs not met by the sovereign grant. He is also pays tax on private capital gains on assets including the private estates of Balmoral in Scotland and Sandringham in Norfolk, as well as investments and private savings.

The sovereign grant, which is linked to crown estate profits two years previously, will now be set for five years from 2027-28 at 20.5%, the Treasury announced, which that year will amount to £99.9m. The crown estate is an independent property and land business that is mandated to act in the national interest.

It was revealed Prince William will no longer personally benefit from the £1.5m annual rent generated by the abandoned Dartmoor prison. William has asked for the sum to be removed from the Duchy of Cornwall – the historical private estate traditionally held by the monarch’s eldest son – from 2026-27 onwards, and the money will be spent on regenerating Princetown, the isolated rural community next to the prison.