While he has been the heir apparent since the age of three, when his mother was proclaimed queen in 1952, the prince could chose his own regnal name, and dump his given name of Charles when he becomes king.
And he wouldn't be the first, as three other British monarchs have chosen to be known by another name when they ascended the throne.
Queen Victoria had been christened Alexandrina Victoria, but took the throne under the name Victoria.
While King Edward VII, Victoria’s eldest son, chose Edward as his regnal title, even though he had been known by his first name of Albert.
And then in 1936, after the abdication crisis, Prince Albert, Duke of York, assumed the throne as King George VI rather than "King Albert".
He may wish to avoid the name because Charles II of England, was known for his Catholic sympathies and Charles I of England, was executed after the English Civil War.
It's thought that instead he might use one of his other names and choose to become King George VII, King Philip, or King Arthur.