Percentage Rates.
Effective date - Annual rate - Monthly rate - Daily rate
Prior to January 1, 1969 - 6 - 0.5 - -
January 1, 1969 - 8 - 0.6667 - -
September 13, 1975 - 12 - 1.0 - -
June 1, 1982 - 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 1: Tom filed a 2016 return reporting tax to pay of $500. He made a $500 payment on February 25, 2019. The interest start date is April 19, 2017, the first day after the due date of the return, which was April 18, 2017. Interest is computed on a daily basis as follows:
4/19/17-12/31/2018 (Annual interest rate / 365 days) x number of days x tax due
(5% / 365) x 622 days x $500 = $42.57
1/1/2019-2/24/19 (Annual interest rate / 365 days) x number of days x tax due
(6% / 365) x 55 days x $500 = $4.52
Total interest: $47.09
Or. Admin. Code § 150-305-0140
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