Seattle Local Guide | 6 min read

King County Property Value Notice: What to Check

By Homespring TaxPublished Aug 16, 2026

Quick answer

When a King County value notice arrives, verify the parcel, the assessment year, the land and improvement values, the mailing date, and the property facts behind the total. Save the notice, calculate the filing window, and investigate the market value separately from the eventual tax bill.

Identify exactly what changed

Confirm the parcel number, owner, situs address, assessment year, and total value. Compare the new land and improvement components with the prior record so you know whether the change came from land, buildings, or both.

The notice is about assessed value for a future tax year. It is not the tax bill and does not by itself show the final dollars due.

Save the date and the document

King County publishes a neighborhood mailing schedule, but the parcel's notice is the document to preserve. The regular petition deadline is July 1 or 60 days after the value notice is mailed, whichever is later.

Record the mailing date, calculate the 60-day point, and confirm the filing date in eAppeals. Keep a copy of the notice and any envelope or delivery record that could matter if timing becomes disputed.

Open the underlying property record

Use King County eReal Property to review the characteristics used in valuation. Look for errors that affect market value, not merely formatting differences.

  • Incorrect living area, lot size, or construction year
  • Wrong property type, quality, condition, or remodeling history
  • Bedrooms, bathrooms, parking, or finished-area errors
  • Missing restrictions, access problems, steep topography, or other site influences

Choose the next step before the window closes

If the record looks accurate, compare the value with relevant sales near the statutory valuation date. If the evidence supports the county value, keep the research and avoid a weak petition. If it supports less, organize the record errors, sales, and condition evidence around one requested value.

An informal conversation with the Assessor can clarify facts, but it does not replace a timely petition. Preserve the formal deadline while any review is pending.

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