The Royal Family is exempt from paying inheritance tax only if a particular rule is followed.

King Charles inherited many assets from the late Queen Elizabeth (Image: Getty)

King Charles’s siblings, Princess Anne, Prince Edward, and Prince Andrew have all missed out on the late Queen Elizabeth’s £380million fortune to avoid paying inheritance tax, according to experts.

The Royal Family is exempt from the standard inheritance tax rules after a clause agreed upon by Sir John Major’s Government in 1993, which stated that any “transfers of assets from one sovereign to his or her successor” avoids the 40 percent charge applied to assets valued at more than £325,000.

It also stated that inheritance passed from the consort of a former sovereign to a sovereign is also exempt from inheritance tax.

Sir Major’s agreement was made at the time to “prevent the dilution of the Crown’s wealth and ensure the continuity of the monarchy’s functioning.”

This mean that if any of the King’s siblings inherited any of their mother’s illustrious wealth and assets, they’d be subjected to inheritance tax.

King Charles’s siblings would not be immune from inheritance tax (Image: Getty)The guidance said: “The monarchy as an institution needs sufficient private resources to enable it to continue to perform its traditional role in national life.”

The Crown Estate has an administering property worth £15.6 billion, but out of its revenue, only 25 percent is given to the monarch as the Sovereign Grant, while the other 75 percent goes to the Treasury.

Charles oversees the Sovereign Grant, which supports the official duties of the Royal Family and was set at £86.3million for 2024-25, while he is now also the sole beneficiary of £27 million income from the Duchy of Lancaster, an ancient portfolio of land, property, and assets which is held in trust for the sovereign.

This private Duchy income is separate from the taxpayer-funded Sovereign Grant.

But according to the Government’s guidance, anyone else inheriting private assets from a sovereign, in this case, the late Queen, would be subject to tax.

It stated: “In relation to assets which can properly be regarded as private, the arrangements provide that inheritance tax will not be paid on gifts of bequests from one sovereign to the next, but will be payable on gifts and bequests to anyone else.”

It comes as earlier this summer Buckingham Palace’s annual accounts were published and showed that the monarchy is to receive a boost of more than £45 million, with a 53 percent jump in its official annual income to more than £130 million.

Soaring profits from the Crown Estate to £1.1 billion mean the taxpayer-funded Sovereign Grant will increase from £86.3 million in 2024/2025 to £132 million in 2025/2026.