Washington Revised Code Title 19. Business Regulations--Miscellaneous § 19.52.020. Highest rate permissible--Setup charges

(1) Except as provided in subsection (4) of this section, any rate of interest shall be legal so long as the rate of interest does not exceed the higher of: (a) Twelve percent per annum; or (b) four percentage points above the equivalent coupon issue yield (as published by the Board of Governors of the Federal Reserve System) of the average bill rate for twenty-six week treasury bills as determined at the first bill market auction conducted during the calendar month immediately preceding the later of (i) the establishment of the interest rate by written agreement of the parties to the contract, or (ii) any adjustment in the interest rate in the case of a written agreement permitting an adjustment in the interest rate. No person shall directly or indirectly take or receive in money, goods, or things in action, or in any other way, any greater interest for the loan or forbearance of any money, goods, or things in action.

(3) Any loan made pursuant to a commitment to lend at an interest rate permitted at the time the commitment is made shall not be usurious. Credit extended pursuant to an open-end credit agreement upon which interest is computed on the basis of a balance or balances outstanding during a billing cycle shall not be usurious if on any one day during the billing cycle the rate at which interest is charged for the billing cycle is not usurious.