Explained | What will be the powers of Britain’s new monarch, King Charles III? ...........According to the Royal Family’s official site, the monarch “has to remain strictly neutral with respect to political matters”. This was evident during the reign of Queen Elizabeth II, who rarely made her political views public. Talking about her weekly private audiences with British Prime Ministers, the late Queen had said in a 1992 documentary: “They know that one can be impartial, so to speak. I think it's rather nice to feel that one's a sort of sponge."
Political leanings aside, the monarch, during most of her 70-year reign, was actively involved in diplomatic activities in the Commonwealth and other countries, which often played a role in mending soured ties, an analysis by the Lowy Institute noted. It gave examples of multiple significant visits to strengthen ties with the United States in the years after an attempt by Britain to invade the Suez Canal, or her 2011 visit to Ireland where she admitted and regretted Britain’s involvement and actions during the 1916 East uprising.
As for the monarch’s constitutional powers or royal prerogatives, here’s the role they still play:
Appointment of Prime Minister and government: The new King will have the power to formally appoint the Prime Minister who enjoys the majority support of MPs. Once the leader of a party wins general elections, the Head of State invites them to Buckingham Palace to form the government. In case no single party achieves an overall majority after an election, by convention, the monarch appoints the individual most likely to have the confidence of the House of Commons.
The monarch also officially dissolves a government ahead of national elections, as per the advice of the Prime Minister. The power of the monarch to dissolve the Parliament of their own accord was removed with the enforcement of the Fixed-term Parliaments Act of 2011, which provided holding five-year Parliaments, with automatic dates of polling and dissolution.
The discretionary power to appoint or dismiss a Prime Minister no longer lies with the monarch. The last time a monarch dismissed a Prime Minister unilaterally was in 1834 when William IV dismissed Lord Melbourne and replaced him with Sir Robert Peel. The Constitution Unit of the UCL noted in its 2016 report that another instance of a level of discretion being exercised was witnessed when “King George V persuaded Ramsay MacDonald not to resign in 1931, when his Labour government broke up, but to head a National government dominated by the Conservatives”.
Opening the Parliament: The new King will open each Parliamentary year with the State Opening Ceremony, during which he will deliver an address about the executive's planned policies and priorities in the House of Lords. Notably, King Charles has already done this once, in May 2022, on his mother’s behalf on account of her health issues.
Assenting legislation: The sovereign gives his/her Royal Assent to the bills passed in the House of Lords and Commons but that is now essentially a rubber-stamping exercise as the last time a bill denied the Royal Assent was in 1707 by Queen Anne. Constitutional law professor Robert Blackburn was quoted by the UCL as pointing out that “the monarch’s role is limited to one of due process, and royal assent is a certificate that the bill has passed through all its established parliamentary procedures”.
Besides these roles, King Charles will also hold audiences with Prime Minister Liz Truss each Wednesday, when she will brief him on the government’s activities; he can ask to see any government paper he wishes to. According to the BBC, he will receive daily dispatches from the administration in a leather box, containing briefings of meetings, documents needing his signature and so on. The King will also be hosting Heads of State visiting the country, besides Ambassadors and High Commissioners. The sovereign also confers Knighthoods to notable personalities annually. .........
Besides the sovereign’s functions as a Head of State mentioned above, they are also the head of the armed forces, delegating power to the Prime Minister to issue orders to be executed by military officials. The King will also be head of the Church of England. The monarchy also engages in welfare or charitable activities. ................
https://www.thehindu.com/news/international/explained-what-powers-will-britains-new-monarch-king-charles-iii-have/article65871099.ece