Wash. Rev. Code § 11.24.010
If any person interested in any will shall appear within four months immediately following the probate or rejection thereof, and by petition to the court having jurisdiction contest the validity of said will, or appear to have the will proven which has been rejected, he or she shall file a petition containing his or her objections and exceptions to said will, or to the rejection thereof. Issues respecting the competency of the deceased to make a last will and testament, or respecting the execution by a deceased of the last will and testament under restraint or undue influence or fraudulent representations, or for any other cause affecting the validity of the will or a part of it, shall be tried and determined by the court.
For the purpose of tolling the four-month limitations period, a contest is deemed commenced when a petition is filed with the court and not when served upon the personal representative. The petitioner shall personally serve the personal representative within ninety days after the date of filing the petition. If, following filing, service is not so made, the action is deemed to not have been commenced for purposes of tolling the statute of limitations.
If no person files and serves a petition within the time under this section, the probate or rejection of such will shall be binding and final.
RCW 11.24.010
Effective dates-1994 c 221: See note following RCW 11.100.035.