If you recently received your Official Property Value Notice from King County and experienced sticker shock, you aren’t alone. Assessed values don’t always accurately reflect the current market — especially for specific property types like townhomes and condos.

Fortunately, Washington state allows you to appeal your assessment to the Board of Equalization (BOE). The process can seem daunting, but by focusing on hard data and bypassing the county’s automated tools, you can build a highly effective case.

Here is a step-by-step guide on how to file a strong property tax appeal in King County for the 2026 assessment year (taxes payable in 2027).

Step 1: Understand the Rules of the Game

The single most important rule is this: The county assessor is presumed correct by law. You cannot argue that your taxes went up too much, or that the percentage increase is unfair. The BOE will instantly dismiss those arguments.

Your only job is to prove that the assessed value exceeds the actual fair market value of your property as of January 1, 2026.

Step 2: Gather Your Evidence (The “Silver Bullet” Comparables)

To prove your case, you need comparable sales (“comps”). Skip the generic Zillow estimates and find 3 to 4 properties that sold around early-to-mid 2026.

Pro-Tips for Finding Comps:

  • Match the Property Type: If you own a condo or townhome, only use other attached homes as comparables. The county often values detached single-family homes differently.
  • Find the Ceiling: Look for a brand-new construction or a highly upgraded luxury unit of similar size that sold for less than your assessed value. If a brand-new build sold for $1.5M, an older unit shouldn’t be assessed at $1.7M.
  • Calculate Price Per Square Foot: Use this metric to expose flaws in the county’s math.

Step 3: Write Your Appeal Narrative

Instead of typing your reasons into small web forms, write a formal appeal narrative, save it as a PDF, and upload it as your primary evidence.

Template:

Property Tax Appeal Narrative Parcel Number: [Your Parcel Number] Taxpayer Name: [Your Name] Property Address: [Your Address] Assessor’s Appraised Value: $[Assessed Value] Taxpayer’s Opinion of Value: $[Your Proposed Value]

Specific Reasons for Appeal: The 2026 assessed value of $[Assessed Value] does not reflect the true and fair market value of this property as of January 1, 2026. The subject property is a [Square Footage] sq ft [Property Type]. The county’s assessment places the value at $[Price per sq ft] per square foot, which significantly exceeds the market ceiling established by comparable sales in [Your City/Neighborhood] during early to mid-2026.

Please consider the following closed sales, which demonstrate that the current assessed value is inflated:

  • Comparable 1: [Address] (Sold for $[Price] on [Date]) [Explain why this is a strong comp. E.g., “This is a brand-new 2026 construction townhome with an identical layout. A 20-year-old condo should not be assessed higher than new construction.”]
  • Comparable 2: [Address] (Sold for $[Price] on [Date]) [Explain comp 2]
  • Comparable 3: [Address] (Sold for $[Price] on [Date]) [Explain comp 3]

These market-based comparables clearly demonstrate that actual market transactions for [Property Type] in this area max out around $[Market Ceiling]. I respectfully ask that the assessment be adjusted to $[Your Proposed Value] to reflect true fair market value.

Step 4: Navigate the eAppeals Portal

King County no longer accepts appeals via email. You must use their eAppeals portal.

  1. Log In: Go to the King County eAppeals login page and sign in to start a new appeal.
  2. Skip the Auto-Search: In Steps 2 through 4, the portal will try to force you to use their comparable search tool. Bypassing this is highly recommended if you already have your own hand-picked, superior Redfin/MLS comps. Click “Skip Steps 2 - 4”.
  3. Enter Your Estimate (Step 5): The system requires you to split your proposed value between “Land” and “Improvements.” Always keep the Land value exactly as the assessor appraised it, and subtract the difference from the Improvements/Buildings row to hit your target total.
  4. Upload Your Evidence (Step 6): Change the dropdown for “Sales Support a Different Value” to Yes. Then select Other as the documentation category, type “Independent Market Comparables”, and upload the PDF narrative you wrote in Step 3.
  5. Upload the Postcard (Step 7): You are legally required to upload a photo or scan of the Official Property Value Notice you received in the mail.
  6. Finalize (Steps 8-10): Fill out any historical purchase info, electronically sign the petition, and hit Submit.

Important: Make sure the status on your dashboard changes from “Incomplete Appeal” to “Processing Appeal.”

What Happens Next?

Once submitted, you play the waiting game. The Assessor’s office will review your evidence. If your comparables are undeniable, they may email you a stipulation offer — an agreement to lower your value without a hearing.

If they don’t stipulate, the BOE will schedule a hearing (usually 4-9 months later). You can choose to attend virtually or let them decide based purely on your uploaded PDF.

Deadline Warning: You only have 60 days from the mailing date printed on your Official Value Notice to file your appeal. Don’t wait until the last minute!