Washington Utilities and Transportation Commission
Commission rules set the customer deposit interest rate at the level of the one-year Treasury Constant Maturity, as calculated by the U.S. Treasury and published in the Federal Reserve's Statistical Release H.15.
As of November 15, 2017, the interest rate that telephone and water companies must pay on the deposits they hold for their customers is 1.55 percent.
For each calendar year, telephone and water company rules use the rate as of November 15 of the previous year.
As of January 16, 2018, the interest rate that gas, electric, and solid waste companies must pay on the deposits they hold for their customers is 1.79 percent.
Gas, electric, and solid waste company rules use the rate as of January 15. Since January 15 was a holiday, the rate used is the rate as of the next business day, January 16, 2018.