Prince Harry lost his UK taxpayer-funded security detail when he moved to the United States
He doesn't have to worry about money. AFP

Being a British royal isn't all bad, as Prince Harry sometimes seems to indicate. He's reportedly about to breeze into a new $10 million fortune, thanks to his late great-grandmother, Queen Elizabeth.

Harry inherits the money on his 40th birthday September 15 from a trust established by the Queen Mother in 1994 when he was just ten years old, the Times of London reports. The trust arrangement guarantees that the income will be tax-free.

Palace sources believe Harry was left a larger portion of the overall trust by Elizabeth, who was 94 when it was set up, because brother William would collect a sizable fortune from the Duchy of Cornwall as heir apparent, according to the newspaper.

The brothers reportedly received the equivalent of $8 million in today's American equivalent when they turned 21, with the bulk of it going to Harry. The rest was to be doled out on their 40th birthdays. William turned 40 two years ago in June.

William inherited $18 million last year when he became heir apparent after his father ascended the crown to become King Charles III, the Times notes.

The trust was a "way in which the Queen Mother could set aside money for when her great-grandchildren were older and a way of passing a slice of her estate down in a tax-efficient way," a palace spokesperson told the paper.

Other beneficiaries of the trust are Princess Anne's children, Zara and Peter Phillips, Prince Andrew's daughters, Beatrice and Eugenie, and the late Princess Margaret's children, David Linley and Lady Sarah Chatto.

Aside from the money set aside for her great-grandchildren the Queen Mother left her entire estate to her granddaughter Queen Elizabeth II.