Washington Administrative Code Title 458 (Department of Revenue)
WAC 458-18-220 — Refunds—Rate of Interest
Agency filings affecting this section (1) Introduction. Interest applies to refunds of taxes made pursuant to RCW 84.69.010 through 84.69.090 in accordance with RCW 84.69.100 . Interest also applies to judgments entered in favor of the plaintiff pursuant to RCW 84.68.030 . (2) Calculation of interest rate. The interest rate is calculated from the equivalent coupon issue yield of the average bill rate for 26-week treasury bills as determined at the first bill market auction conducted after June 30th of the calendar year preceding the date the taxes were paid. (3) Interest rates. The following rates are applied to the amount of the judgment or the amount of the refund, until paid: Year tax paid Auction Year Rate 1984 1983 9.29% 1985 1984 11.27% 1986 1985 7.36% 1987 1986 6.11% 1988 1987 5.95% 1989 1988 7.04% 1990 1989 8.05% 1991 1990 8.01% 1992 1991 5.98% 1993 1992 3.42% 1994 1993 3.19% 1995 1994 4.92% 1996 1995 5.71% 1997 1996 5.22% 1998 1997 5.14% 1999 1998 5.06% 2000 1999 4.96% 2001 2000 5.98% 2002 2001 3.50% 2003 2002 1.73% 2004 2003 0.95% 2005 2004 1.73% 2006 2005 3.33% 2007 2006 5.09% 2008 2007 4.81% 2009 2008 2.14% 2010 2009 0.29% 2011 2010 0.21% 2012 2011 0.08% 2013 2012 0.15% 2014 2013 0.085% 2015 2014 0.060% 2016 2015 0.085% 2017 2016 0.340% 2018 2017 1.130% 2019 2018 2.085% 2020 2019 2.040% 2021 2020 0.165% 2022 2021 0.050% 2023 2022 2.50% 2024 2023 5.26% 2025 2024 5.115% 2026 2025 4.145% [Statutory Authority: RCW 84.34.065 , 84.34.141 , 84.34.360 , and 84.69.100 . WSR 26-01-183, s 458-18-220, filed 12/23/25, effective 1/1/26; WSR 24-24-089, s 458-18-220, filed 12/3/24, effective 1/1/25; WSR 24-03-001, § 458-18-220, filed 1/3/24, effective 1/3/24; WSR 23-01-007, § 458-18-220, filed 12/7/22, effective 1/1/23; WSR 22-04-028, § 458-18-220, filed 1/24/22, effective 1/1/22; WSR 21-01-210, § 458-18-220, filed 12/23/20, effective 1/1/21; WSR 20-02-056, § 458-18-220, filed 12/24/19, effective 1/1/20; WSR 19-02-058, § 458-18-220, filed 12/27/18, effective 1/1/19; WSR 18-01-147, § 458-18-220, filed 12/20/17, effective 1/1/18; WSR 17-01-162, § 458-18-220, filed 12/21/16, effective 1/1/17; WSR 16-01-035, § 458-18-220, filed 12/9/15, effective 1/1/16; WSR 15-01-166, § 458-18-220, filed 12/23/14, effective 1/1/15; WSR 14-01-059, § 458-18-220, filed 12/13/13, effective 1/1/14; WSR 13-02-053, § 458-18-220, filed 12/26/12, effective 1/1/13; WSR 12-01-040, § 458-18-220, filed 12/13/11, effective 1/1/12. Statutory Authority: RCW 84.69.100 . WSR 11-02-017, § 458-18-220, filed 12/29/10, effective 1/1/11; WSR 10-07-038, § 458-18-220, filed 3/10/10, effective 4/10/10; WSR 08-24-094, § 458-18-220, filed 12/2/08, effective 1/2/09; WSR 07-24-037, § 458-18-220, filed 11/30/07, effective 12/31/07; WSR 06-21-059, § 458-18-220, filed 10/16/06, effective 11/16/06; WSR 05-22-096, § 458-18-220, filed 11/1/05, effective 12/2/05; WSR 04-24-101, § 458-18-220, filed 12/1/04, effective 1/1/05; WSR 03-24-014, § 458-18-220, filed 11/20/03, effective 12/21/03; WSR 02-23-081, § 458-18-220, filed 11/19/02, effective 12/20/02; WSR 02-03-039, § 458-18-220, filed 1/8/02, effective 2/8/02; WSR 00-24-106, § 458-18-220, filed 12/6/00, effective 12/31/00; WSR 99-24-033, § 458-18-220, filed 11/23/99, effective 12/24/99. Statutory Authority: RCW 84.08.010 , 84.08.070 and 84.69.100 . WSR 99-01-066, § 458-18-220, filed 12/14/98, effective 1/1/99; WSR 98-01-177, § 458-18-220, filed 12/23/97, effective 1/1/98; WSR 97-02-068, § 458-18-220, filed 12/31/96, effective 1/1/97; WSR 96-01-093, § 458-18-220, filed 12/19/95, effective 1/1/96; WSR 95-06-044, § 458-18-220, filed 2/24/95, effective 3/27/95; WSR 94-05-063, § 458-18-220, filed 2/11/94, effective 3/14/94. Statutory Authority: RCW 84.08.010 and 84.69.100 . WSR 93-06-096, § 458-18-220, filed 3/3/93, effective 4/3/93; WSR 92-17-027, § 458-18-220, filed 8/11/92, effective 9/11/92; WSR 91-15-024, § 458-18-220, filed 7/11/91, effective 8/11/91. Statutory Authority: RCW 84.69.100 and 84.08.010 (2). WSR 89-10-067 (Order PT 89-6), § 458-18-220, filed 5/3/89; WSR 88-07-003 (Order PT 88-3), § 458-18-220, filed 3/3/88. Statutory Authority: RCW 84.69.100 as amended by 1987 c 319 and 84.08.010 (2). WSR 87-19-141 (Order PT 87-7), § 458-18-220, filed 9/23/87.]
Source: official text