Although Prince William and Prince Harry are both employed, the royal brothers, together with Kate Middleton are still receiving allowance from Prince Charles for their official activities.

E! Online reported that the Duke and Duchess of Cambridge, both 33, and 30-year-old Harry are being funded by their royal dad for their travels, charitable works and other royal expenses.

Clarence House released an annual review of the Duke and Duchess of Cornwall's expenditures, and reported that William, Harry and Kate receive a total amount of ₤2.965 million, about $4.667 million, in 2014 up to the end of March this year.

The report however did not provide a specific breakdown on how much each is getting and on how they have spent their millions.

Majority of their royal funding comes from Prince Charles' private income, from his country estate profit that amounts to ₤19.845 million (about $31.24 million) in a year. This source of income supports most of the costs of the royal family's public and charity projects.

Only £1.736 million (about $2.73 million) of the funds come from the Sovereign Grant and £498,000 (about $784,486) from the government and taxpayers' money.

A taxpayer himself, England's future king has also reportedly spent on eco-projects like programs on reducing greenhouse gas emissions. According to Clarence House, he "has been a leader in helping to foster good sustainability practice for 40 years."

Prince Charles also shares his love for nature with this 23-month-old grandson, Prince George, who helps him in gardening at his Highgrove House estate.

A royal insider told US Weekly that "George recently helped his granddad plant a balsam poplar tree and a winter orange lime tree."

"They love to garden together," the insider added.

The 66-year-old Duke also plans to renovate a tree house at Highgrove, where Prince William and Prince Harry used to play as kids. Constructed in 1988, the tree house would be a fun place to visit for Prince George and his baby sister, Princess Charlotte.