Percentage Rates.
Effective date - Annual rate - Monthly rate - Daily rate
January 1, 1969 - 8 - 0.6667 - -
September 13, 1975 - 6 - 0.5 - -
June 1, 1982 - 12 - 1.0 - 0.0329
June 1, 1983 - 18 - 1.5 - 0.0493
August 1, 1986 - 17 - 1.4167 - 0.0466
January 1, 1987 - 16 - 1.3333 - 0.0438
January 1, 1988 - 11 - 0.9167 - 0.0301
January 1, 1993 - 8 - 0.6667 - 0.0219
January 1, 1995 - 10 - 0.8333 - 0.0274
January 1, 1999 - 9 - 0.75 - 0.0247
January 1, 2001 - 10 - 0.8333 - 0.0274
February 1, 2002 - 8 - 0.6667 - 0.0219
February 1, 2003 - 7 - 0.5833 - 0.0192
January 1, 2004 - 6 - 0.5 - 0.0164
January 1, 2005 - 5 - 0.4167 - 0.0137
January 1, 2006 - 7 - 0.5833 - 0.0192
January 1, 2007 - 9 - 0.75 - 0.0247
January 1, 2009 - 6 - 0.5 - 0.0164
January 1, 2010 - 5 - 0.4167 - 0.0137
January 1, 2013 - 4 - 0.3333 - 0.0110
January 1, 2017 - 5 - 0.4167 - 0.0137
January 1, 2018 - 5 - N/A - 0.0137
January 1, 2019 - 6 - N/A - 0.0164
January 1, 2021 - 4 - N/A - 0.0110
January 1, 2023 - 6 - N/A - 0.0164
January 1, 2024- 8- N/A - 0.0219
The daily interest rates shown above are rounded for illustrative purposes.
Example: Tom filed his 2016 return and paid the tax due on April 6, 2017. On November 1, 2018, Tom filed a 2016 amended return to claim a $1,000 refund. The refund was paid on December 11, 2018. The interest start date is June 2, 2017, the 45th day after the original return was due (April 18, 2017). Interest is computed on a daily basis as follows:
6/2/2017-12/11/2018 - (Annual interest rate / 365 days) x number of days x amount of refund
(5% / 365) x 558 days x $1,000 = $76.44
Total interest: $76.44
Or. Admin. Code § 150-305-0142
Publications: Contact the Oregon Department of Revenue for information about how to obtain a copy of the publication referred to or incorporated by reference in this rule pursuant to ORS 183.360(2) and ORS 183.355(1)(b).
Statutory/Other Authority: ORS 305.100 & 305.220
Statutes/Other Implemented: ORS 305.220