When property subject to taxation is withheld, overlooked, or from any other cause is not listed and assessed, the county treasurer shall, when apprised thereof, at any time within two years from the date at which such assessment should have been made, demand of the person, firm, corporation, or other party by whom the same should have been listed, or to whom it should have been assessed, or of the administrator thereof, the amount the property should have been taxed in each year the same was so withheld or overlooked and not listed and assessed, together with six percent interest thereon from the time the taxes would have become due and payable had such property been listed and assessed.
Iowa Code § 443.12
99 Acts, ch 174, §3, 7