Prince William will inherit £10 million when he turns 30 next month.
The second in line to the British throne will become eligible to be awarded his share of money from the estate of his late mother, Princess Diana - who died in a car crash in 1997 - when he reaches the milestone age on June 21.
While William and his wife Catherine rent a cottage in Wales and have an apartment at Kensington Palace in London, royal insiders believe they may use the money to buy a country home close to William's father, Prince Charles', Highgrove estate in Gloucestershire.
A source told the Daily Mail newspaper: "It will be quite a handy sum if he wants to buy his and Catherine's first family house. What else would he need the money for?"
However, William may chose not to inherit the full £10 million in order to provide more money for his younger brother Prince Harry.
Diana's estate is comprised of stocks and shares, jewellery, cash from her divorce settlement from Charles, dresses and other personal belongings at her Kensington Palace apartment.
In her original 1993 will, the princess stipulated both princes would be entitled to their entire share of the capital on reaching 25.
However, details of the will were changed by a variation order granted by the High Court in December 1997, three months after her premature death in a Paris car crash, which changed the age that her sons could ask for the capital to 30.