Washington Revised Code Title 4. Civil Procedure § 4.84.015. Costs in civil actions for the recovery of money only--When plaintiff considered the prevailing party

(1) In any civil action for the recovery of money only, the plaintiff will be considered the prevailing party for the purpose of awarding costs, including a statutory attorney fee, if: (a) The defendant makes full or partial payment of the amounts sought by the plaintiff prior to the entry of judgment; and (b) before such payment is tendered, the plaintiff has notified the defendant in writing that the full or partial payment of the amounts sued for might result in an award of costs.

(2) For the purposes of this section, “plaintiff” includes a counterclaimant, cross-claimant, and third-party plaintiff, and “defendant” includes a party defending a counterclaim, cross-claim, or third-party claim.

(3) A party may demand, offer, or accept the payment of statutory costs before the entry of judgment in an action.

(4) This section may not be construed to (a) authorize an award of costs if the action is resolved by a negotiated settlement or (b) limit or bar the operation of cost-shifting provisions of other statutes or court rules.