While some royal engagements are affected by the upcoming UK General Election on 4 July, the King is expected to attend his birthday parade – formally known as Trooping the Colour - on 15 June.
But Charles could make some changes to this year's ceremony, starting with the transport he chooses to use during the parade.
It's been widely reported that amid the King's ongoing cancer treatment that he may travel by carriage instead of horseback, to avoid any risk to his health.
Last year, Charles took the salute as sovereign for the first time as he rode Noble, a seven-year-old black mare presented as a gift from the Royal Canadian Mounted Police.
It marked the first time a monarch had ridden on horseback since Queen Elizabeth II last rode in 1986.
And while the late Queen welcomed members of her extended family onto the Buckingham Palace balcony to watch the flypast, since Charles' reign began in 2022, only working royals have been given the privilege.
However, in the light of the King's ongoing treatment and the Princess of Wales's absence from public life as she undergoes preventative chemotherapy for her cancer diagnosis, it's possible that Charles may extend the invitations to wider members of the family, including his nieces and nephews.
The Prince of Wales delighted royal fans last week as he invited his cousins, Princess Beatrice, Princess Eugenie, Peter Phillips, Zara Tindall and her husband Mike, to join him at a Buckingham Palace garden party.
And the King has also reportedly asked Lady Gabriella Kingston to attend the celebrations with the royals, just months after the unexpected death of her husband and financier, Thomas Kingston.
What is Trooping the Colour?
Over 1,400 parading soldiers, 200 horses and 400 musicians come together each June in a great display of military precision, horsemanship and fanfare to mark the King's official birthday.
The parade moves from Buckingham Palace, down The Mall to Horse Guards Parade, where the ceremony takes place. Members of the royal family join the procession, either on horseback or in carriages.
After the ceremony, the royals return to Buckingham Palace to watch the flypast from the balcony. Take a look back at the royals assembling to watch the military spectacle at last year's Trooping the Colour in the clip below...
According to the Household Division, the British Army's regimental flags were historically described as 'colours' because they display the uniform and insignia of the soldiers from different military units.
The army used these flags so that soldiers could easily spot their unit when they were on the battlefield because without modern-day communication it was too easy to become disorientated or separated from their regiment.
Officers would regularly march up and down in front of soldiers, known as 'trooping,' with their flags on displays, known as 'colours' so that everyone would know which ones would belong to which regiment.
Why does the King have two birthdays?
While Charles' actual birthday is on 14 November, historically the sovereign's birthday is officially marked in June with the Trooping the Colour ceremony if their actual birthday does not land in the summer months.
The reason, in typical British fashion, comes down to the weather. The tradition started in 1748 with George II, who was born in chilly November. Instead of risking his subjects catching a cold, he combined his birthday celebration with the annual spring parade known as Trooping the Colour.