They say the Duchy of Cornwall private estate has been “generating tens of millions of dollars a year” and “done so without paying corporation taxes like most businesses in Britain are obliged to, and without publishing details about where the estate invests its money.”
Which tax is paid doesn’t really matter. And if it’s not a corporation then corporation tax really isn’t payable anyway.
As it happens, Charles has been paying 45% on the income from the estate. Top rate of income tax. So, that’s solved then, isn’t it?