If you have filed an untimely petition, or in other words, a petition that was turned in after the deadline, you may be eligible for a Good Cause Waiver. Under WAC 458-14-056 (3), certain exceptions could be excused allowing your petition to be filed if accepted by the Board. Once this form is turned in to the BOE, the Board will vote whether or not to accept the untimely petition. You cannot appeal the decision of the Board to the Washington State Board of Tax Appeals.
Link to Good Cause Waiver:
Good Cause Waiver