(A) Rental income received by a taxpayer shall be included in the computation of net profits from business activities under § 880.03 (C) through (G) only if and to the extent that the rental, ownership, management or operation of the real estate from which such rentals are derived (whether so rented, managed or operated by a taxpayer individually or through agents or other representatives) constitutes a business activity of the taxpayer in whole or in part.
(B) Where the gross monthly rental of any and all real properties, regardless of number and value, aggregates in excess of $250 per month, it shall be prima-facie evidence that the rental, ownership, management or operation of such properties is a business activity of such taxpayer, and the net income of such rental property shall be subject to tax, provided that in the case of commercial property, the owner shall be considered engaged in a business activity when the rental is based on a fixed or fluctuating percentage of gross or net sales, receipts or profits of the lessee, whether or not such rental exceeds $250 per month, and provided, further, that the person who operates a licensed rooming house shall be considered in business whether or not the gross income exceeds $250 per month.
(Ord. 15-72, passed 1-3-1972)