The tax imposed by this chapter is due and payable at the death of the decedent, and if not paid within fifteen months after the date of death, must bear interest at the rate of one percent per month or fraction thereof to be computed from the expiration of fifteen months after death until the amount is paid. The tax commissioner may for good cause waive all or any part of any interest that attaches under the provisions of this section.
N.D.C.C. § 57-37.1-07