How to appeal your property taxes in Washington
The petition is free. The deadline is printed on your value notice, not on a calendar. And the whole case comes down to one thing: what comparable homes actually sold for.
How Washington decides what you owe
Washington assesses every home at 100% of market value as of January 1 of the assessment year, and reassesses every year. The bill you pay always lags one year behind: the 2026 assessment funds the bill payable in 2027.
That makes the appeal question simple to state: did your assessor overshoot what your home was actually worth on January 1? The proof is comparable sales — homes like yours that sold near that date, preferably before it, since assessments are based on sales prior to the assessment date. Washington makes sale prices public through real estate excise tax records, so every comp is verifiable.
If the answer is yes, you petition your county Board of Equalization — an independent citizen board, not the assessor's office — on the state Department of Revenue's Taxpayer Petition form (REV 64 0075) or your county's version of it. Filing is free in every county we've verified, and you don't need a lawyer. The state's overview lives on the Department of Revenue's appeals page.
Your deadline is on your value notice — not a calendar
Here's the rule (RCW 84.40.038): your petition is due the later of July 1 of the assessment year or 30 days after the mailing date printed on your Official Property Value Notice — and counties can extend that to 60 days. King, Pierce, and Snohomish all give you 60.
So a notice mailed September 18 in King County is appealable into mid-November. Counties mail notices in batches from late spring into fall, which means there is no single "Washington appeal deadline" — only yours. County boards have publicly warned about solicitation mailers that claim a flat July 1 deadline to panic homeowners. Don't take the bait in either direction: read the mailing date off your own notice and count from there. Missed it? Boards can accept a late petition when you show good cause — and you'll be ready on day one next year.
The full picture — the statute, the counties that adopted 60 days, and the July 1 myth, debunked — is in our Washington appeal deadline guide.
| County | Window after notice mails | Filing fee | Board page |
|---|---|---|---|
| King County | 60 days (or July 1, whichever is later) | Free | Board of Equalization |
| Pierce County | 60 days (or July 1, whichever is later) | Free (per county page) | Board of Equalization |
| Snohomish County | 60 days (or July 1, whichever is later) | Free | Board of Equalization |
The petition, step by step
- 1. Check your value notice. Find the mailing date and the assessed value. Your window runs from that date.
- 2. Build the evidence first. Comparable sales near January 1, adjusted for differences — this is the part that decides the case. Since SB 6077 (2026), the comps you list on the petition can only be changed later with new evidence filed at least 21 business days before your hearing, so they need to be right the first time.
- 3. File the free petition. The DOR form (or your county's version), with your estimate of value, your specific reasons, and your comps on it. File online where offered (King County's eAppeals), otherwise by mail or in person. A letter of disagreement alone isn't accepted — boards require the approved form.
- 4. Choose the written record, or a hearing. Most boards let you waive appearing and decide on your written evidence. Before any hearing, the assessor must share their evidence with you at least 28 business days ahead.
- 5. Watch for a settlement. Assessors often review petitions and propose an agreed reduction — a stipulation — without a hearing at all. Your evidence packet is exactly what they look at.
One honest caveat: the board can raise, lower, or confirm a value, and the assessor is presumed correct until clear, cogent and convincing evidence shows otherwise. That's why this whole page keeps coming back to evidence quality — and why, when the numbers say your assessment is fair, the right move is not to file. We'll tell you that for free.
Where we come in
The free check compares your assessed value against a market estimate for your home — anywhere in Washington — and tells you honestly whether an appeal looks worthwhile. If it does, the Appeal Evidence Kit ($35, one time) builds the case: comparable sales selected and adjusted for your property, a defensible estimate of value, a professional evidence packet, and a Washington roadmap that formats everything for the petition form. You file it — free — and keep every dollar you save. We never take a percentage.
Curious how the same evidence-first approach works for California homes? See how California appeals work, how the two states' systems compare, and what makes appeal evidence strong.
No signup. Not everyone qualifies — we'll tell you either way.
Washington appeal questions, answered straight
There is no fixed statewide date — your deadline is personal. By law (RCW 84.40.038), your petition is due the LATER of July 1 of the assessment year or 30 days after the mailing date printed on your Official Property Value Notice. Many counties extend that to 60 days, including King, Pierce, and Snohomish. Find the mailing date on your notice and count from there. If you missed it, your county board can accept a late petition when you show good cause.
Usually not — and this matters. July 1 is only a floor: you always have at least 30 days (often 60) from your notice's mailing date, whichever is LATER. Some counties mail notices in batches into the fall, so real deadlines often run to November or beyond. County boards have publicly warned that solicitation mailers spread a false flat 'July 1 deadline.' Read the date off your own notice.
Filing a petition with your county's Board of Equalization is free in every county we've verified — no filing fee, no lawyer required. The real cost of an appeal is the work: finding comparable sales near the January 1 assessment date, adjusting them for differences, and presenting them the way the board weighs evidence.
The board has legal authority to raise, lower, or confirm your value, and the assessor's value is presumed correct unless clear, cogent and convincing evidence shows otherwise. That's a high bar — and it's exactly why an appeal should lead with verified comparable sales rather than a general complaint. An increase is uncommon when similar homes genuinely sold for less than your assessed value; if the evidence doesn't support a case, the honest answer is not to file.
Usually not. Most Washington boards let you check a box to waive appearing and decide on your written evidence — which makes a complete evidence packet the whole case. If you do attend, hearings are informal: no courtroom, no lawyer needed.
One assessment year. Washington revalues every property every year, so a win lowers the bill that assessment funds (payable the following year) and the county starts fresh the next January 1. Checking your new value notice each year is how you keep the savings — the evidence from one year makes the next year's check fast.
Sales of comparable homes, as close to January 1 of the assessment year as possible — preferably before it, since assessments are based on sales prior to that date. Washington is a sale-price disclosure state (real estate excise tax records are public), so sale prices are verifiable; some counties ask for each comparable sale's excise tax number on the petition. Since a 2026 law change (SB 6077), the comps you list on your petition can only be swapped later if you find new evidence, submitted at least 21 business days before your hearing — so get the comps right before you file. The assessor must share their evidence with you at least 28 business days before the hearing.
California assessments are capped by Proposition 13 and appeals argue a Prop 8 decline in value against fixed statewide windows (July 2 to September 15 or November 30). Washington assesses every home at 100% of market value every year, the deadline runs from your own value notice, filing is free, and a win covers that one assessment year. Same core evidence — comparable sales — different law around it. Overassessed is purpose-built for each.