And the Fabian Society wants the Queen and her relatives to produce fully transparent accounts of all their private and public income.
Since 1993, the Queen had voluntarily paid income and capital gains tax but that does not go far enough, according to the society.
In its document The Future of the Monarchy, the Fabian Society said funding of the whole Royal Family should become transparent with full accounts provided by a new Head of State Office.
And the whole Royal Family should pay tax on private income and wealth.
This would include for the first time inheritance tax on private properties such as Balmoral and Sandringham Castles.
The status of ownership of other Royal assets such as works of art should be clarified as part of the accounting and tax review, the report said.
The whole income of the Royal Family – public and private – should be consolidated into a single publicly accountable revenue stream subject to a vote in Parliament.
The report also says that the Monarch should be allowed to retire, Catholics should be allowed to succeed to the Throne, the Sovereign should not remain head of the Church of England, heirs to the Throne should not longer require the consent of the Queen to marry, and the oldest child regardless of sex should succeed to the Monarchy.
Crowe Clark Whitehill , the top 20 accountancy firm, has announced the promotion of Chris Mould to partner
The latest opinions from Accountancy Age on Making Tax Digital, and outline plans to evolve the UK's corporate governance regime
Five million taxpayers are ow using digital personal tax accounts (PTA) as part of the making tax digital strategy, HMRC said
UK-based non-doms have paid ten times more tax than the average taxpayer, raising concerns over the Brexit impact on non-dom contributions and therefore, the economy