Following changes to the law in the 1990s, quite rightly, no inheritance tax will be payable on the Queen's estate

King Charles III will inherit the estate and due to a special legal clause that was introduced to avoid the erosion of the royal family’s wealth, he will not be liable for inheritance tax (IHT) at 40% as the estate will be IHT exempt.

He automatically inherited the estate, the monarch’s primary source of income, while his eldest son, Prince William inherited the Duchy of Cornwall estate, valued at more than £1bn, from his father.

The new King will avoid inheritance tax on the estate, estimated to be worth more than £600m, due to a rule introduced in 1993 by Sir John Major’s government to guard against the royal family’s assets being wiped out if two monarchs died within a short period of time of each other.

At the time, the then PM told parliament: ‘The concerns that I would have were the arrangements to be any other would be the danger of the assets of the monarchy being salami-sliced away by capital taxation through generations, thus changing the nature of the institution in a way that few people in this country would welcome.’