Interest on Refunds

# (1)

(1) Adjustment to statutory rate. For refunds owing on or after January 1, 2026, unless specifically provided by statute or by rule, every refund arising under any law administered by the department will bear interest at the rate of eight percent annually. For historic rates, see section (4) of this rule.

# (2)

(2) Interest start date.

(a) As provided in OAR 150-314-0240, when a refund of individual income tax is attributable to tax withheld by an employer, or when a refund of individual income tax, corporate excise tax, or corporate income tax is attributable to estimated taxes, the interest starting date is 45 days after the return was due or 45 days after the return was filed, whichever is later.

(b) The interest start date for a refund of estate tax is 45 days after the return was due, 45 days after the original return was filed, or 45 days after the tax was paid, whichever is later.

(c) The interest start date for refunds not described in (2)(a) or (2)(b) is 45 days after the return was due or 45 days after the date the tax was paid, whichever is later.

# (3)

(3) Interest periods.

(a) An interest period is one full calendar day beginning with the interest start date. Interest will be computed on a daily basis. The daily rate is based on a 365-day year.

(b) The daily interest rate is calculated by dividing the annual interest rate by 365 without rounding.

# (4)

(4) The following table shows interest rates used by the department to compute interest due to taxpayers on refunds.