Wash. Rev. Code § 84.48.065 (2026)

(1)(a) The county assessor or treasurer may cancel or correct assessments on the assessment or tax rolls which are erroneous due to manifest errors in description, double assessments, clerical errors in extending the rolls, and such manifest errors in the listing of the property that do not involve a revaluation of property, except in the case that a taxpayer produces proof that an authorized land use authority has made a definitive change in the property's land use designation. In such a case, correction of the assessment or tax rolls may be made notwithstanding the fact that the action involves a revaluation of property. Manifest errors that do not involve a revaluation of property include the assessment of property exempted by law from taxation or the failure to deduct the exemption allowed by law to the head of a family. When the county assessor cancels or corrects an assessment, the assessor must send a notice to the taxpayer in accordance with RCW 84.40.045, advising the taxpayer that the action has been taken and notifying the taxpayer of the right to appeal the cancellation or correction to the county board of equalization, in accordance with RCW 84.40.038. When the county assessor or treasurer cancels or corrects an assessment, a record of the action must be prepared, setting forth therein the facts relating to the error. The record must also set forth by legal description all property belonging exclusively to the state, any county, or any municipal corporation whose property is exempt from taxation, upon which there remains, according to the tax roll, any unpaid taxes.

(b) Except as otherwise provided in this subsection (1)(b), no manifest error cancellation or correction, including a cancellation or correction made due to a definitive change of land use designation, may be made for any period more than three years preceding the year in which the error is discovered. However, a manifest error cancellation or correction may be made for a period more than three years preceding the year in which the error is discovered if authorized by the county legislative authority and the manifest error cancellation or correction would result in a refund or reduction of taxes for a property owner.

(2)(a) In the case of a definitive change of land use designation, an assessor must make corrections that involve a revaluation of property to the assessment roll when:

(i) The assessor and taxpayer have signed an agreement as to the true and fair value of the taxpayer's property setting forth in the agreement the valuation information upon which the agreement is based; and

(ii) The assessment roll has previously been certified in accordance with RCW 84.40.320.

(b) In all other cases, an assessor must make corrections that involve a revaluation of property to the assessment roll when:

(i) The assessor and taxpayer have signed an agreement as to the true and fair value of the taxpayer's property setting forth in the agreement the valuation information upon which the agreement is based; and

(ii) The following conditions are met:

(A) The assessment roll has previously been certified in accordance with RCW 84.40.320;

(B) The taxpayer has timely filed a petition with the county board of equalization pursuant to RCW 84.40.038 for the current assessment year;

(C) The county board of equalization has not yet held a hearing on the merits of the taxpayer's petition.

(3) The assessor must issue a supplementary roll or rolls including such cancellations and corrections, and the assessment and levy have the same force and effect as if made in the first instance, and the county treasurer must proceed to collect the taxes due on the rolls as modified.

Contingent effective date—2001 c 187: See note following RCW 84.70.010.

Application—2001 c 187: See note following RCW 84.40.020.

Application—Severability—Part headings not law—Referral to electorate—1997 c 3: See notes following RCW 84.40.030.

Effective date—1992 c 206: See note following RCW 82.04.170.