King Charles is set for a huge £45m pay rise with an increase of more than 50% in his official annual income, official accounts reveal.

Profits of £1.1bn from the crown estate – a percentage of which funds the monarchy – mean the sovereign grant, which supports the official duties of the royal family, will rise from £86m in 2024-25 to £132m in 2025-26.

The monarchy currently receives 12% of the crown estate profits to fund its work as well as to fund the 10-year, £369m renovation of Buckingham Palace. Royal aides said the increase will be used to complete the palace reservicing programme by 2027.

The sovereign grant will be reviewed in 2026-27 to reassess the amount handed over to the palace and ensure it is an “appropriate level”.

Royal accounts also show that the Prince of Wales received £23.6m income from the Duchy of Cornwall in his first full year after inheriting the land and property owning estate from his father.

The duchy surplus meets the costs of the official, charitable and private lives of the Prince and Princess of Wales and their three children. As his father did, William pays a standard rate tax on the amount once official costs have been deducted, aides said.

The significant increase in the sovereign grant in 2025-6 and 2026-7 “will be used to fund the final stages of the Buckingham Palace reservicing programme, enabling it to be complete both on time and on budget,” said Michael Stevens, the king’s Keeper of the Privy Purse.

Once this is accomplished, he said “a reduction in the absolute amount of the sovereign grant will be sought as part of the royal trustees review in 2026-27, through primary legislation”, to ensure that the work of the royal family “continues to be funded at an appropriate level”.

Buckingham Palace’s annual accounts, released on Tuesday, cover the first full financial year of the king’s reign. They include the months after the Charles and Catherine each had a cancer diagnosis, with both being kept from public-facing duties from January onwards.

It emerged that Frogmore Cottage, the house on the Windsor estate that was renovated at a cost of £2.4m to the taxpayer for the Duke and Duchess of Sussex, remains empty. The renovation costs have since been paid back to the public purse.

After the departure of the Sussexes from the UK, Princess Eugenie, the Duke of York’s daughter, lived there with her family. It is currently empty and there are no new tenants, aides confirmed.

During the year there were more than 2,300 official engagements by members of the royal family in the UK and overseas, compared with more than 2,700 last year.

Charles undertook 464 official engagements despite his cancer diagnosis, with the queen carrying out 201, of which 103 were joint engagements.

The report also showed £600,000 from the sovereign grant was spent on the coronation and events surrounding it last year, with the total cost to the sovereign grant overall coming to £800,000.

This figure covered internal costs such as staffing and palace receptions, plus any furnishings or costumes that could be reused later on, including the adjusting of the Imperial State Crown and the king and queen’s coronation robes.

Charles’s increased income follows a more than doubling of profits for the crown estate, the national portfolio of historical and commercial land-holdings, to £1.1bn in 2023-24, up from £443m the previous year.

This was driven by proceeds from the sale of options and leases on offshore wind projects on the seabed surrounding the British Isles. The crown estate, as legal owner of the seabed, has responsibility for auctioning offshore wind rights.

The sovereign grant is funded by the taxpayer in exchange for the king’s surrender of the revenue from the crown estate and is calculated on funds two years in arrears.

The royal household had been receiving 25% of the crown estate’s profits to fund their official duties as well as the renovations, but last year the government and royal household agreed that would be cut to 12%, partly in anticipation of the likely bonanza resulting from the auction of offshore wind licenses. If the 25% formula had continued, the monarchy would have received £275m in 2025-26.

A National Audit Office (NAO) report released on Tuesday revealed that the palace renovation project has been well managed, but structural damage and the discovery of asbestos, which led to cost increases, “could have been foreseen”. It said the 10-year project’s net expenditure at the end of March was £238.9m – 65% of the budget.

Gareth Davies, the head of the NAO, said: “Updating decades-old plumbing, heating and electrics, as well as adding new lifts and lavatories in one of the UK’s most famous buildings, is a significant undertaking which has been well-handled to date.

“Sound planning and project management has enabled the programme to remain within budget to date and respond well to challenges such as the pandemic. While risks remain as the programme draws to a close, if these continue to be managed effectively, the result should represent good value for money.”