Prince William would prefer that his wife Kate, the Duchess of Cambridge, be called "Princess Catherine", officials said.
A commoner by birth, Kate Middleton was given the title Her Royal Highness Catherine, Duchess of Cambridge, after her marriage to William, the second in line to the throne.
The prince's spokesman said William was "honoured" to become the Duke of Cambridge. But he let it be known that he would prefer to remain Prince William and his wife to become "Princess Catherine", according to the Daily Telegraph.
The Buckingham Palace said if people wanted to call Catherine "princess", they were welcome to do so.
Paddy Harverson, the communications secretary of Prince Charles, the Prince of Wales, said the public may be encouraged to use the names Prince William and Princess Catherine.
When Prince Charles married Camilla Parker Bowles in 2005, she took the title "Duchess of Cornwall", while Sophie Helen Rhys-Jones, who married Charles' brother Prince Edward in 1999, was given the title "Countess of Wessex".