(2) When the time for filing a return of income is extended at the request of the taxpayer, interest at the rate established under ORS 305.220, from the time the return was originally required to be filed to the time of payment, shall be added and paid. [1969 c.166 §2; 1971 c.354 §3; 1973 c.402 §17; 1975 c.593 §13; 1980 c.20 §24; 1982 s.s.1 c.16 §6; 1987 c.293 §59b; 2017 c.278 §7]