Wash. Rev. Code § 60.32.020
No person shall be entitled to the lien given by RCW 60.32.010, unless he or she shall, within ninety days after he or she has ceased to perform labor for such person, company, or corporation, filed for record with the county auditor of the county in which said labor was performed, or in which is located the principal office of such person, company, or corporation in this state, a notice of claim, containing a statement of his or her demand, after deducting all just credits and offsets, the name of the person, company, or corporation, and the name of the person or persons employing claimant, if known, with the statement of the terms and conditions of his or her contract, if any, and the time he or she commenced the employment, and the date of his or her last service, and shall serve a copy thereof on said person, company, or corporation within thirty days after the same is so filed for record.
Any number of claimants may join in the same notice for the purpose of filing and enforcing their liens, but the amount claimed by each claimant shall be separately stated.
RCW 60.32.020