Wash. Rev. Code § 24.06.190
Amendments to the articles of incorporation shall be made in the following manner:
A corporation's board of directors may amend the articles of incorporation to change the name of the corporation, without seeking member or shareholder approval. With respect to amendments other than to change the name of the corporation, the board of directors shall adopt a resolution setting forth the proposed amendment and directing that it be submitted to a vote at a meeting of members and shareholders, which may be either an annual or a special meeting. Written or printed notice or, if specifically permitted by the articles of incorporation or bylaws of the corporation, notice by electronic transmission, setting forth the proposed amendment or a summary of the changes to be effected thereby shall be given to each member and shareholder entitled to vote at such meeting within the time and in the manner provided in this chapter for the giving of notice of meetings of members and shareholders. The proposed amendment shall be adopted upon receiving at least two-thirds of the votes which members or shareholders present in person or by mail or by electronic transmission at such meeting or represented by proxy are entitled to cast: PROVIDED, That when any class of shares or members is entitled to vote thereon by class, the proposed amendment must receive at least two-thirds of the votes of the members or shareholders of each class entitled to vote thereon as a class, who are present in person, by mail, by electronic transmission, or represented by proxy at such meeting.
Any number of amendments may be submitted and voted upon at any one meeting.
RCW 24.06.190