WAC 458-18-220. Refunds — Rate of interest

(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% 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%