(2) If the declaration is filed on or before April 18 of the taxable year, the estimated tax shall be paid in four equal installments. The first installment shall be paid at the time of the filing of the declaration, the second and third on June 15 and September 15 of the taxable year, and the fourth on January 15 of the succeeding year.
(3) If the declaration is filed after the due date of the prior taxable year return without regard to extensions and not after June 15 of the taxable year, and is not required by ORS 316.577 to be filed on or before April 18 of the taxable year, the estimated tax shall be paid in three equal installments. The first installment shall be paid at the time of the filing of the declaration, the second on September 15 of the calendar year, and the third on January 15 of the succeeding taxable year.
(4) If the declaration is filed after June 15 and not after September 15 of the taxable year, and is not required by ORS 316.577 to be filed on or before June 15 of the taxable year, the estimated tax shall be paid in two equal installments. The first installment shall be paid at the time of filing of the declaration, and the second on January 15 of the succeeding taxable year.
(5) If the declaration is filed after September 15 of the taxable year and is not required by ORS 316.577 to be filed on or before September 15 of the taxable year, the estimated tax shall be paid in full at the time of filing of the declaration.
(6) If the declaration is filed after the time prescribed in ORS 316.577, subsections (3) to (5) of this section shall not apply. Instead, there shall be paid at the time of filing all installments of estimated tax that would have been payable on or before such time if the declaration had been filed within the time prescribed in ORS 316.577, and the remaining installments shall be paid at the times at which, and in the amounts in which, they would have been payable if the declaration had been so filed.
(7) If a taxpayer does not file a declaration but files a return on or before January 31 of the succeeding year and pays in full the amount stated as due on the return:
(a) If the declaration is not required to be filed during the taxable year, but is required to be filed on or before January 15, the return shall be considered as the declaration; and
(b) If the tax shown on the return, as reduced by the sum of the credits against the tax allowed for purposes of this chapter, is greater than the estimated tax shown in an earlier declaration, or in the last amendment thereof, the return shall be considered as the amendment of the declaration permitted by ORS 316.563 (4) to be filed on or before January 15.
(8) In the application of this section to a taxable year beginning on any date other than January 1, there shall be substituted for the 15th or last day of the month specified in this section, the 15th or last day of the corresponding month.
(9) An individual may pay an installment of the estimated tax before the date prescribed for its payment.
(10) Any payment of estimated tax received by the Department of Revenue shall first be applied to underpayments of estimated tax due for any prior installment due for the taxable year. Any excess amount shall be applied to the installment that next becomes due after the payment was received. [1980 c.7 §§16,20; 1981 c.678 §3; 1985 c.603 §7; 1987 c.293 §22; 1993 c.730 §43; 2003 c.46 §42; 2021 c.9 §2]