RCW 82.08.185: Total price of any transaction—Adjustment—Sales tax.

(1) The total price of any transaction may be adjusted as provided in RCW 1.100.010.

(2) The sales tax imposed under this chapter must be calculated on the selling price of goods, services, or other products subject to sales tax without regard to any rounding applied under RCW 1.100.010.

(3) Any rounding permitted under RCW 1.100.010 applies solely to the cash tendered in an in-person retail sales transaction and does not alter the measure of the sales tax due under this chapter.

(4) Nothing in this section authorizes the rounding of the amount of sales tax due.

(5) For the purposes of this section, "total price" and "transaction" have the same meanings as provided in RCW 1.100.010.