Section 316.588 - When interest on underpayment not imposed(1) Interest accruing under ORS 316.587 shall not be imposed for any taxable year if the tax shown on the return for the taxable year (or, if no return is filed, the tax), minus the sum of any credits allowable for purposes of this chapter, including the credit allowable under ORS 316.187, is less than the amount established by rule adopted under ORS 316.563(2).(2) For purposes of this section: (a) If an amended return is filed on or before the return due date (determined with regard to any extension of time granted to the taxpayer), then the term "return" means the amended return.(b) If during initial processing of the return the Department of Revenue adjusts the amount of tax due, then the term "tax shown on the return" means the tax as adjusted by the department. This paragraph shall not apply if it is ultimately determined that the adjustment was improper. 1987 c.293 §22c; 1993 c.726 §35b; 1999 c.90 §19; 2001 c.660 §5