Anonymous. When I was 30, I had a nanny job that was at least 10 hours a day, plus I would spend up to 3 hours a day commuting, sometimes more. It almost killed me and I was tired all the time and honestly, I was not a great nanny to this family because of it.
Therefore, Mountbatten-Windsor is the surname of all male (and unmarried female) descendants of Prince Philip and Queen Elizabeth II; this includes Prince Charles, Prince William and Prince Harry. Because Prince Harry and Price William use the title Prince, they do not use the last name Mountbatten-Windsor. They use the surname Wales because they are the sons of the Prince of Wales. Although Royals don't tend to use a last name, in the instance of a marriage, for example, Prince William's last name is Mountbatten-Windsor. This is the surname of all descendants of Prince Philip and Queen Elizabeth II (excluding females who marry).
Prince William's official last name is: Mountbatten-Windsor. That is quite a mouthful. The name comes from the merging of names of the Queen and Prince Phillip in 1960. Her last name was Windsor, and his was Mountbatten. Internet searches for What is Prince William's last name are up 1199 percent this week.