To do that, we follow an established methodology. (See Gomme and Rupert 2004 for a justification of this methodology.) We classify the compensation of employees as unambiguous labor income (UL), and we classify corporate profits, rentalincome, net interest income, and depreciation as unambiguous capital income (UK).
To the contrary, if the rental activity does not rise to the level of a trade or business, the fact that it is no longer treated as passive courtesy of the real estate professional rules will not change the fact that the rentalincome is considered net investment income.