For purposes of determining the interest rate established under ORS 305.220:
(1) In the case of a refund of tax ordered by the Oregon Tax Court or the Oregon Supreme Court and arising under any law administered by the Department of Revenue, if the refund is not paid by the department within 60 days after the date of the order, the interest rate provided under ORS 305.220 shall be four percent greater than the annual interest rate provided under ORS 305.220, but only with respect to interest periods that begin 61 days after the date the order is entered.
(2)(a) In the case of a notice of assessment pursuant to any law administered by the department, if the deficiency is not paid within 60 days after the date of the notice of assessment, the interest rate provided under ORS 305.220 shall be four percent greater than the annual interest rate provided under ORS 305.220, but only for interest periods that begin 61 days after the date of notice of assessment.
(b) In the case of an assessment under ORS 305.265 (12), if the delinquency is not paid within 60 days after the date of the assessment, the interest rate provided under ORS 305.220 shall be four percent greater than the annual interest rate provided under ORS 305.220. The increased rate shall apply only for interest periods that begin 61 days after the date of notice of the delinquency.
(3) If the deficiency assessment is appealed to the Oregon Tax Court without prior payment of tax, then notwithstanding subsection (2) of this section, the increased rate of interest shall commence only for interest periods that begin 61 days after the date that the order of the Oregon Tax Court or the Oregon Supreme Court affirming the deficiency is entered.