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How to appeal a property tax assessment

How to appeal your property assessment from the Department of the Assessor.

When to appeal your property tax

The Assessor’s office mails valuation change notices each year between May and November of the assessment year. Your assessment will determine the amount of taxes you pay in the following year. You can appeal your assessment within 60 days of receiving your valuation notice. 

Assessment year

The assessment year is the year before the tax is due. For example, a 2019 assessment determines taxes payable in 2020, thus the 2019 assessment year corresponds to the 2020 tax year. Under very limited conditions, late petitions or appeals for previous assessment years may be accepted. Petitions must be postmarked by July 1 of the assessment year or within 60 calendar days after the date of the value change notice (or other notice of determination).

How to find the due date

Lookup your property address or parcel to find the appeal filing due date. Once you have selected your property, your appeal due date will be shown. If the year for the due date displayed still shows 2018, then your 2019 assessment value change notice has not yet been sent. Please wait to file appeal your 2019 assessment appeal until after you receive your 2019 valuation change notice.

When an appeal may not be required

If you feel a mistake has been made in valuing your property, it is recommended that you contact the Department of Assessments directly before filing an appeal at 206-296-7300 or assessor.info@kingcounty.gov. You can review your property parcel or account information online using eReal Property at Assessor-Online Services or with the Assessor’s staff to make sure an error has not been made.

What you will need to appeal

You must submit a petition from for each land parcel. Even if you are submitting online, be sure you have access to all the information we need. The board cannot consider incomplete petitions.

Each complete petition form must include

  1. Assessor’s parcel number
  2. Taxpayer name and address
  3. Taxpayer’s representative, if applicable (must include power of attorney)
  4. Property description to include property address, parcel size, zoning, and general building information
  5. Value as listed by the Assessor
  6. Your opinion of value
  7. Specific reasons why you believe the Assessor’s value does not reflect the true and fair market value of your property. Your petition must include sufficient information or statements to apprise the Board and the Assessor of the reasons why you believe the Assessor’s determination is incorrect. Assessment comparisons of other properties, percentage of value increases, personal hardship, amount of tax, and other matters unrelated to market value cannot be considered. {WAC 458-14-056(5)}
  8. Taxpayer’s signature and date
  9. A copy of the Assessor’s revaluation change notice or other determination notice

Don't forget the evidence

Approximately 25% of the property values appealed to the Board result in some type of reduction.  Compelling market-based evidence is the key. Remember, the issue before the Board is the market value of your property. You will need to furnish evidence that demonstrates the Assessor’s valuation exceeds your property’s fair market value. When gathering evidence and formulating arguments, it is important to keep in mind that, by law, the Assessor is presumed to be correct. The burden of proof is on you to show that the Assessor’s determination is incorrect.  

  • Successful forms of evidence include
  • Comparable sales and/or sales of the subject property
    • Comparable properties do not have to exactly match your property. The best examples are sales in your neighborhood, with similar land and improvement features, which sold closest to the valuation date at issue. Assistance in finding comparable sales is available
      • On the Assessor’s website or by calling 206-296-7300
      • With the Tax Advisors Office (for residential properties only) or by calling 206-477-1060
      • Through realtors and title companies
  • Contractor estimates of costs to repair building or land defects
  • Letters or documents from government agencies and/or experts regarding development limitations
  • Deeds describing easements that impact value
  • Independent appraisals
  • Photographs of features or conditions that you believe diminish your property’s market value
  • Maps showing proximity to high traffic areas, access limitations, or other detractors

The appeal process

  • Before you begin

    You must submit a petition from for each land parcel. Even if you are submitting online, be sure you have access to all the information we need. The board cannot consider incomplete petitions.

    Each complete petition form must include

    1. Assessor’s parcel number
    2. Taxpayer name and address
    3. Taxpayer’s representative, if applicable (must include power of attorney)
    4. Property description to include property address, parcel size, zoning, and general building information
    5. Value as listed by the Assessor
    6. Your opinion of value
    7. Specific reasons why you believe the Assessor’s value does not reflect the true and fair market value of your property. Your petition must include sufficient information or statements to apprise the Board and the Assessor of the reasons why you believe the Assessor’s determination is incorrect. Assessment comparisons of other properties, percentage of value increases, personal hardship, amount of tax, and other matters unrelated to market value cannot be considered. {WAC 458-14-056(5)}
    8. Taxpayer’s signature and date
    9. A copy of the Assessor’s revaluation change notice or other determination notice
  • Fill out the petition form

    Find, download, and fill out forms for your petition on our appeals forms page. For real property appeals, use the real property petition form and for personal property appeals, use the personal property petition form. All documents must be filed in duplicate.
  • There are 2 ways to send in an appeal

    You can send your petition online or by mail. We do not accept petitions by email.

    Online

    Using eAppeal for your real estate appeal allows you to access, update, and track your petition throughout the process. You can also instantly view appeal related documents sent by the Board of Equalization and the King County Assessor. You will receive an email confirmation within 24 hours of submitting.

    Create an account on eAppeals

    By mail

    Send your completed petition forms, attachments, and evidence to 

    King County Board of Equalization
    516 Third Avenue, Room 1222
    Seattle, WA 98104

    Petitions either 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 (or other notice of determination).

    You will need to submit separate petitions for each parcel or property you'd like to appeal.

    Request an expedited hearing

    Hearings are generally scheduled in the order the appeals are received. However, once you complete your evidence submission and you have received the Assessor’s Response, you will be eligible for an expedited hearing. To request an expedited hearing, please email boe@kingcounty.gov

  • The Board of Equalization (BOE) receives and reviews the appeal

    We will assign the appeal a status of pending, complete, or active.

    If the appeal is not accepted, we consider the appeal in a pending status and notify you about required actions and options.

    If the appeal is accepted, we notify you with details about your hearing date (this may take 6 months or more due to appeal volumes).

  • Assessor sends response to the appeal

    The Assessor will send response to you at least 21 business days before the hearing date. You must submit all evidence submissions at least 21 business days before the hearing date.
  • A hearing is held on the appeal.

    You can participate by phone or allow the Board to make a decision based on submitted materials without participating (administrative review hearing).
  • The Board's decision

    You and the Assessor will be sent a Board Order with our decision within 45 days after the hearing date.

    If all parties agree on the decision, the process is over.

    If you or the Assessor disagree with our decision, parties can file an appeal with the Washington State Board of Tax Appeals within 30 days of the mailing date of our decision.

    If the board decreases the value

    The Assessor’s records will be adjusted. The Treasurer’s Office will either send a revised tax statement if the decision occurs before April 30 or October 31 of the tax year, or issue a refund if your full year’s taxes have already been paid.

    This process may take a couple of months to complete.

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