Charles, who technically became head of the British monarchy after the death of Elizabeth II, will be officially crowned king on Saturday.
This is reported by the BBC.
The ceremony will take place at St James's Palace in London before a ceremonial body known as the Inauguration Board.
At the meeting, the death of Queen Elizabeth II will be announced and the traditional address will be read. The king, who takes the name Charles III, will then attend a second meeting with the group, where he will make his first statement and vow to preserve the Church of Scotland.
Later, Charles III will be officially proclaimed as the new king, and cannons will be fired from grounds across the city.
Flags, flown at half-mast in national mourning, will be flown for 24 hours starting at 1pm local time on Saturday to mark the king's announcement, before being lowered again.
Meanwhile, Queen Elizabeth II will lie in repose at St Giles' Cathedral in Edinburgh while preparations are made for her funeral, which is expected in about 10 days.
The coffin will then be flown to London, where hundreds of thousands of people will be allowed to flock to Westminster Hall over four days.