All deficiency determinations, exclusive of penalty, shall bear interest at the modified adjusted rate per month, or fraction thereof, established pursuant to Section 6591.5, from the last day of the calendar month following the reporting period for which the amount or any portion thereof should have been returned until the date of payment.
(Added by Stats. 1994, Ch. 912, Sec. 17. Effective September 28, 1994. Operative July 1, 1995, by Sec. 26 of Ch. 912.)