Ever since Queen Elizabeth ascended the throne, the British national anthem has been "God Save the Queen". However, when King Charles ascends to the throne, that will change, and Britain will return to the national anthem, which has actually been used more throughout history. The song "God Save the King", which dates back to 1745, will be the new national anthem. Because the throne will again appear king instead of queen. But there won't be many new changes to the national anthem. The current national anthem is very similar to the original one. It just replaces "queen" with "king"!
Another change is that Charles's face will appear on British currency and stamps. Interestingly, according to the British newspaper Express, there are rumors that King Charles has prepared a portrait to be printed on the currency. These portraits will be used for new currency and stamps when the time comes. Of course, the currency and stamps currently in circulation will not immediately become worthless. They may even be considered collector's treasures by some. According to MyLondon**, these old currencies will be "phased out" as more new currencies are created and used more widely.