On April 29, 2011, the day of wedding of Prince William of Wales and Catherine Middleton, Queen Elizabeth II had created her grandson Duke of Cambridge, Earl of Strathearn and Baron Carrickfergus, titles relating respectively to places in England, Scotland and Northern Ireland, three of the constituent countries of the United Kingdom.

The letters patent granting these titles received the great seal on May 26, 2011.

The day after King Charles III ascended the throne, he created the Duke of Cambridge Prince of Wales and Earl of Chester during his speech to the nation.

Will he, or has he, issued letters patent creating his son Prince of Wales and Earl of Chester? Does he need to or was his announcement sufficient?

The future King Charles II of England, Scotland and Ireland was designated Prince of Wales, at or around his eighth birthday, though he was never formally invested but is still recognized as a Prince of Wales. So maybe letters patent are not necessary?