(1) If a demand for payment under RCW 23B.13.280 remains unsettled, the corporation shall commence a proceeding within sixty days after receiving the payment demand and petition the court to determine the fair value of the shares and accrued interest. If the corporation does not commence the proceeding within the sixty-day period, it shall pay each dissenter whose demand remains unsettled the amount demanded.

(2) The corporation shall commence the proceeding in the superior court of the county where a corporation's principal office, or, if none in this state, its registered office, is located. If the corporation is a foreign corporation without a registered office in this state, it shall commence the proceeding in the county in this state where the registered office of the domestic corporation merged with or whose shares were acquired by the foreign corporation was located.

(3) The corporation shall make all dissenters, whether or not residents of this state, whose demands remain unsettled, parties to the proceeding as in an action against their shares and all parties must be served with a copy of the petition. Nonresidents may be served by registered or certified mail or by publication as provided by law.

(4) The corporation may join as a party to the proceeding any shareholder who claims to be a dissenter but who has not, in the opinion of the corporation, complied with the provisions of this chapter. If the court determines that such shareholder has not complied with the provisions of this chapter, the shareholder shall be dismissed as a party.

(5) The jurisdiction of the court in which the proceeding is commenced under subsection (2) of this section is plenary and exclusive. The court may appoint one or more persons as appraisers to receive evidence and recommend decision on the question of fair value. The appraisers have the powers described in the order appointing them, or in any amendment to it. The dissenters are entitled to the same discovery rights as parties in other civil proceedings.

(6) Each dissenter made a party to the proceeding is entitled to judgment (a) for the amount, if any, by which the court finds the fair value of the dissenter's shares, plus interest, exceeds the amount paid by the corporation, or (b) for the fair value, plus accrued interest, of the dissenter's after-acquired shares for which the corporation elected to withhold payment under RCW 23B.13.270.