How to Appeal Your Property Tax in Washington: Step-by-Step Guide
In Washington, a value appeal is a petition to your county board of equalization. Under RCW 84.40.038(1), it is due on the latest of three dates: July 1 of the assessment year, 30 days after the assessor mails the notice, sends it electronically, or notifies you electronically that it is available, or a window of up to 60 days if your county’s legislative authority has adopted one.
Washington filing deadlines at each level
| Step | Body | Deadline rule | Source |
|---|---|---|---|
| Petition to change assessed value | County board of equalization | The latest of: July 1 of the assessment year; 30 days after the notice is mailed, sent electronically, or the assessor notifies you electronically that it is available; or up to 60 days if the county legislative authority has adopted a longer limit | RCW 84.40.038(1) |
| Late petition | County board of equalization | Filed “within a reasonable time” after the deadline, with good cause from the statutory list | RCW 84.40.038(2) |
| Appeal of the county board’s decision | State Board of Tax Appeals | Notice of appeal within 30 days after the board’s decision is mailed | RCW 84.08.130(1) |
| Court review of a Board of Tax Appeals decision | Superior court; for a formal hearing, review under the Administrative Procedure Act | Formal hearing: petition for review within 30 days after service of the final order (RCW 34.05.542(2)). Informal hearing: no appeal to superior court; a refund suit on tax paid under protest must be started by June 30 of the year after the tax became payable (RCW 84.68.020, 84.68.060) | RCW 82.03.180; RCW 34.05.542; RCW 84.68.060 |
The 60-day option is set county by county, and a county that adopts it cannot change it for three years (RCW 84.40.038(1)). The Department of Revenue’s petition form states the same rule: filed or postmarked “by July 1 of the current assessment year or 30 days after the date of mailing of the change of value or other determination notice (up to 60 days in those counties that the Legislative Authority has extended the deadline).” Ask your county board which window applies; your change-of-value notice must carry “a brief statement of the procedure for appeal to the board of equalization” (RCW 84.40.045(2)). A petition sent by mail must be postmarked by the deadline. If the deadline falls on a Saturday, Sunday or holiday, you have until the next business day (WAC 458-14-056(4)).
RCW 84.40.038 was last amended in 2014 (2014 c 97 § 407). None of the Code Reviser’s tables of RCW sections affected by the 2024, 2025 or 2026 sessions lists it.
One county’s window: King County
King County uses the longer period. Its Board of Appeals and Equalization says petitions must be “postmarked, hand delivered to our office, or filed online by the latter of July 1st of the assessment year or within 60 days from the mailing date printed on the value notice.” King also runs an online eAppeal portal and does not accept petitions by email. Those details are King County’s alone. Check your own county board for its window and filing options.
What goes into a Washington petition
RCW 84.40.038(1) requires a petition “on forms prescribed or approved by the department of revenue,” and it says a petition that is not properly completed “may not be considered by the board.” The statewide form is the Taxpayer Petition to the County Board of Equalization for Review of Real Property Valuation Determination, REV 64 0075 (July 26, 2023 revision). The statute also accepts forms the Department has approved. File the petition in duplicate (WAC 458-14-056(2)). The form adds: “If filing after July 1, a copy of the determination notice must be attached to this petition.”
WAC 458-14-056(5) spells out what “properly completed” means. A petition “that merely states the assessor’s valuation is too high or the property taxes are excessive, or similar types of statements, is not properly completed and will not be considered by the board.” You don’t need all your evidence on the day you file. Anything you add later must be provided to the assessor and the board (by postmark) at least 21 business days, excluding legal holidays, before the hearing (WAC 458-14-056(5), 458-14-066(3)). The assessor has to give you the comparable sales it used within 60 calendar days of your request, and at least 21 business days before your hearing (WAC 458-14-066(2)).
On evidence, WAC 458-14-087 limits the board to sales “made within five years of the date of the petition.” Those sales must be adjusted to their value as of January 1 of the revaluation year. More weight goes “to similar sales occurring closest to the assessment date which require the fewest adjustments.”
The burden you carry at the county board
RCW 84.40.0301 presumes the assessor’s value is correct, “but this presumption shall not be a defense against any correction indicated by clear, cogent and convincing evidence.” The Department’s rule, WAC 458-14-046(6), explains how that works in practice. If you show by clear, cogent and convincing evidence that the assessor’s method was flawed, or that a specific value within the assessment is wrong, the standard for the contested issues drops to a preponderance of the evidence.
The board meets on July 15, or within 14 days after the assessor certifies the roll, whichever is later (RCW 84.48.010(4)). The county legislative authority must form the board before July 15 each year (RCW 84.48.010(1)). The board must send you its decision within 45 days of your hearing (RCW 84.48.010(2)). Everyone who testifies swears or affirms under penalty of perjury (WAC 458-14-076(4)).
Board of Tax Appeals and the courts
An appeal from the county board goes to the Washington State Board of Tax Appeals. File a notice of appeal within 30 days after the county board’s decision is mailed. RCW 84.08.130(1) says: “There shall be no fee charged for the filing of an appeal.” An appeal is heard informally unless a party elects a formal hearing. The assessor or the taxpayer can make that election within 20 days of receiving the notice of appeal (RCW 82.03.140(1)).
A value can go up on appeal, but only so far. RCW 84.08.060 bars the Board of Tax Appeals from raising the value above “the larger of either the valuation of the property by the county assessor or the valuation of the property assigned by the county board of equalization.” You can also ask to skip the county hearing and go straight to the state board, but only when “the assessor, the owner… and a majority of the county board of equalization agree” that a direct appeal is appropriate. Even then, the Board of Tax Appeals “may reject the appeal,” and the county board must then hear it (RCW 84.40.038(3)).
After the state board, the route depends on the hearing type (RCW 82.03.180). A decision from a formal hearing is reviewed only under the Administrative Procedure Act, RCW 34.05.510 through 34.05.598; the petition for review must be filed with the court and served on the agency, the office of the attorney general and all parties of record “within thirty days after service of the final order” (RCW 34.05.542(2)). The Board of Tax Appeals says that “an informal appeal cannot be appealed to Superior Court.” The other route is a separate refund lawsuit under RCW 84.68.020: you pay the tax “under written protest setting forth all of the grounds” and then sue in superior court to recover it. That lawsuit cannot be started “after the 30th day of the next succeeding June following the year in which said tax became payable” (RCW 84.68.060). If you may want court review of the valuation decision itself, elect a formal hearing at the Board of Tax Appeals.
For how levies and the senior exemption work, see the Washington property tax guide. The property tax calculator shows what a changed value does to the bill.
Common Washington appeal questions
I filed late. Will the county board still hear me?
Only for good cause, and only if you filed “within a reasonable time” after the deadline. RCW 84.40.038(2) lists the qualifying causes. They include death or serious illness in the immediate family; being away from the notice address for more than 15 of the allowed days when the deadline falls after July 1; incorrect written advice from board, assessor or property tax advisor staff; natural disaster; and postal delay or loss documented by the postal service. The board must waive the deadline if you were not sent a revaluation notice, your value did not change from the prior year, and your property is in an area the assessor revalued that year, provided the petition is filed within a reasonable time after the deadline. Its decision on a waiver is final and cannot be appealed.
My appeal from last year is still pending. Do I need to file again?
Yes, if the assessor sends a new value. WAC 458-14-056(6) says the taxpayer “is required to file a timely petition with the board in order to preserve the right to appeal the change in valuation,” even while an earlier appeal sits with the board, the Board of Tax Appeals or a court.
Can the county board raise my value?
Yes. RCW 84.48.010(1)(a) tells the board to raise any property “returned below its true and fair value,” after giving the owner at least five days’ written notice. If the board raises your value, the increase takes effect 30 days after the order is served or mailed. A timely appeal to the Board of Tax Appeals holds it off until that board decides (WAC 458-14-116(5)(b)).
I bought my house after July 1 for well under the assessed value. Can I still appeal?
Possibly. WAC 458-14-127(1)(c) lets the board reconvene when a bona fide buyer acquired the property in an arm’s length sale after July 1 and on or before December 31 of the assessment year and “the sale price was less than ninety percent of the assessed value.” The request must reach the board by April 30 of the tax year that follows the board’s regular session.
Does a win at the county board carry forward?
No. WAC 458-14-116(4)(c) says “An order issued by the board only applies to the assessment year that was appealed to the board.” The Board of Tax Appeals is different. Under RCW 84.08.130(2), it can make its order last “up to the end of the assessment cycle used by the assessor, if there has been no intervening change in the value.”