Seattle Local Guide | 8 min read

King County Property Tax Appeal Evidence Checklist

By Homespring TaxPublished Aug 16, 2026

Quick answer

A complete King County appeal should identify the parcel and valuation date, state one supported requested value, explain the strongest comparable sales, document material record or condition issues, and preserve proof of timely filing. Quality and relevance matter more than the number of exhibits.

Build a one-page case summary

Lead with the parcel number, assessed value, requested value, valuation date, and a short explanation of why the difference exists. This gives the reviewer a map for the exhibits that follow.

Use a requested value supported by the complete evidence. Avoid asking for a round reduction that is disconnected from the sales or documented property facts.

Verify the property facts

Download or save the county property record and mark each material error. Pair the disputed field with reliable support such as plans, permits, measurements, photographs, inspection findings, or contractor estimates.

  • Official Property Value Notice and parcel record
  • Photos labeled by room, defect, date, and location
  • Repair estimates that describe the work rather than only a total price
  • Documents showing easements, access limits, restrictions, or site problems

Create a comparable-sales grid

Search for arm's-length transactions near the valuation date and within the subject's market segment. For each sale, show the date, price, location, property type, size, age, condition, lot, view, and other major value drivers.

Explain why each sale is comparable and whether it is superior or inferior to the subject. A small, consistent group is more useful than a long list of unexplained addresses.

Audit the packet before filing

Check that every exhibit is readable, labeled, and referenced in the summary. Remove duplicate screenshots and material that does not help establish market value.

  1. Confirm the parcel-specific deadline and submission method.
  2. Make sure the petition is complete and signed where required.
  3. Save the confirmation, final packet, and file names exactly as submitted.
  4. Calendar later evidence and hearing deadlines immediately.

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