King County Property Tax Appeal, Washington

Travis Bunn·Updated July 22, 2026

Watch: How to appeal your property taxes in King County

King County, Washington's most populous county with over 2.4 million residents, encompasses the Seattle metropolitan area from the Puget Sound to the Cascade Mountains. Home to major cities including Seattle, Bellevue, and Kent, the county faces significant property tax burdens with a median annual tax bill of $7,292 - the highest in Washington state and well above the national median. With a median home value of $885,200, King County's property values are nearly 50% higher than the state median of $602,200 and more than double the national median of $360,600, making property tax appeals particularly important for homeowners struggling with rising assessments.

Notable cities: Seattle, Bellevue, Kent, Renton, Auburn

Median Home

$885,200

Tax Rate

0.82%

Annual Tax

$7,292

Population

2,400,000

On the typical King County home, valued near $885,200 at the county’s effective tax rate of 0.82%, an over-assessment of even 10% means you are overpaying year after year until you appeal it. Here is how to find out if yours qualifies.

2026 Appeal Deadline: July 1, 2026, or within 60 days of the valuation notice mailing date, whichever is later

This year's appeal window has passed in most of Washington. Order now and we re-run your numbers free when the window reopens, so your evidence is ready the day your next notice lands.

You have until July 1 of the assessment year OR 60 days from the date your valuation notice was mailed, whichever gives you more time. Assessment notices are typically mailed February through March (though some areas receive notices on a rolling basis May-November), so the July 1 deadline applies to most homeowners. The deadline is firm - late filings are almost always rejected.

See if your King County home is over-assessed

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Washington craftsman home among evergreens. King County appeal guide.

How King County Assesses Property

100%of market value

Assessed by: King County Department of Assessments

Assessment cycle: annual

Notices typically mailed: February through March (rolling basis May-November for some areas)

In Washington state, properties are assessed at 100% of their market value, meaning your assessed value should equal what your property would sell for on the open market. For example, if your home's market value is $885,200 (the King County median), at Washington's 100% assessment ratio your assessed value would be $885,200, resulting in approximately $7,258 in annual taxes at the county's effective rate of 0.82%. There is no assessment ratio to calculate - the assessed value equals the market value as of January 1 of the assessment year.

The Appeal Process

Appeals are heard by the County Board of Equalization. The Board of Equalization schedules hearings typically within 6 months of filing. Hearings are typically 15-30 minutes and can be conducted by phone (most petitioners choose the phone option). You present your comparable sales evidence to a panel of BOE members, the Assessor's representative also presents their valuation, and the board issues a written decision.

Contact the King County Assessor's office at 206-296-7300 or assessor.info@kingcounty.gov before filing to ensure there are no factual errors in your property record - many issues can be resolved through this informal review without filing a formal appeal

Gather evidence showing your property's true market value as of January 1 of the assessment year, including comparable sales from the 12 months leading up to January 1, photos of property condition issues, contractor repair estimates, or professional appraisals

File your petition online through the eAppeals portal at blue.kingcounty.gov/Assessor/eAppeals/ or by mail (in duplicate) by July 1 or within 60 days of your valuation notice mailing date, whichever is later - include your parcel number, current assessed value, your proposed value, and specific reasons why the assessment is incorrect

Submit all evidence to both the Board and Assessor at least 21 business days before your hearing - label exhibits clearly (Comparable Sales Analysis, Property Condition Photos, etc.) and focus on market-based evidence that demonstrates your assessed value exceeds fair market value

Attend your hearing before the King County Board of Equalization, which typically lasts 15-30 minutes and can be conducted by phone - you'll present your evidence and the Assessor will present theirs, with the Board applying a 'clear, cogent, and convincing evidence' standard to determine if your assessment should be reduced

Receive the Board's written decision within 45 days - if they reduce your value, your tax bill is recalculated and you'll receive either a revised tax statement or refund if you've already paid

If unsatisfied with the Board's decision, you may appeal to the Washington State Board of Tax Appeals within 30 days of the decision's mailing date - this is a more formal process with stricter evidence rules

Required form: Real Property Petition Form (available online through eAppeals or downloadable)

Filing Methods

online:File through King County eAppeals portal at https://blue.kingcounty.gov/Assessor/eAppeals/ - recommended for fastest processing and ability to track your appeal

mail:Mail to Board of Appeals and Equalization, 500 Fourth Ave, ADM-LJ-0210, Seattle, WA 98104 - must file in duplicate

Evidence to Bring

Comparable property sales near January 1 of the assessment yearProfessional appraisalsPhotos of property condition issuesContractor repair estimatesDocumentation of easements or other factors affecting value

King County Assessor Contact

King County Department of Assessments

Phone: 206-296-7300

Address: King Street Center, 201 South Jackson Street, Room 708 (KSC-AS-0708), Seattle, WA 98104

Website: https://kingcounty.gov/en/dept/assessor

Online Portal: https://blue.kingcounty.gov/Assessor/eAppeals/

Hours: Monday through Friday, 8:30 a.m. to 4:30 p.m.

Tax Exemptions in King County

Senior Citizen and Disabled Persons Exemption

30% to 90% reduction depending on income level

Reduces or freezes assessed value for tax purposes for eligible senior citizens and disabled persons

Eligibility: Age 61 or older (or age 60+ and retired due to physical disability), own and occupy the home at least 9 months per year, household income of $84,000 or less for 2026, and meet equity requirementsDeadline: December 31

Disabled Person Exemption

30% to 90% reduction based on income level

Same benefits as senior exemption for disabled homeowners who meet income and eligibility requirements

Eligibility: Disabled as defined by Social Security or the VA, own and occupy the home as primary residence, household income of $84,000 or less, and meet equity requirementsDeadline: December 31

Disabled Veteran Exemption

30% to 90% exemption based on disability rating and income

Property tax exemption for qualifying veterans with service-connected disabilities

Eligibility: Veterans with an 80%+ service-connected disability rating and qualifying income levels. Surviving spouses of qualified veterans may also be eligibleDeadline: December 31

King County Appeal Statistics

Success Rate

25%

King County Appeal Packet · $49

Comparable sales evidence, county-specific filing guide, and professional cover letter. Enter your address to get started.

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Frequently Asked Questions

What is the deadline to appeal my property taxes in King County?

The deadline to appeal your King County property tax assessment is July 1, 2026, or within 60 days of the date your valuation notice was mailed, whichever is later. Assessment notices are typically mailed February through March, though some areas receive notices on a rolling basis from May through November. The deadline is firm and late filings are almost always rejected, so it's critical to note the exact mailing date on your valuation notice and mark your calendar immediately. Missing the deadline means you lose your right to appeal for that assessment year.

How do I file a property tax appeal in King County online?

To file your appeal online, go to the King County eAppeals portal at blue.kingcounty.gov/Assessor/eAppeals/ and click 'File a new appeal.' You'll need to enter your parcel number, current assessed value, and your proposed value, then fill in the petition form explaining why the assessment is incorrect. Upload your evidence documents (comparable sales, photos, contractor estimates) as labeled exhibits, and submit the form - you'll receive a confirmation number immediately. The eAppeals system allows you to track your appeal throughout the process and instantly view documents sent by the Board of Equalization and the Assessor.

What is the homestead exemption worth in King County?

King County offers a senior citizen and disabled persons exemption rather than a traditional homestead exemption. This program can reduce your property taxes by 30% to 90% depending on your income level, property value, and taxing district. To qualify, you must be age 61 or older, own and occupy your home as your primary residence at least 9 months per year, and have a household income of $84,000 or less for 2026. The exemption freezes or reduces your assessed value for tax purposes, potentially saving eligible homeowners thousands of dollars annually. Applications are typically due by December 31.

What happens at a Board of Equalization hearing in King County?

At a King County Board of Equalization hearing, you present your evidence to a panel of BOE members showing why your assessed value is too high, typically using comparable sales from near January 1 of the assessment year. The hearing typically lasts 15-30 minutes and can be conducted by phone (which most petitioners choose). The Assessor's representative also presents their valuation and may respond to your evidence. The Board applies a 'clear, cogent, and convincing evidence' standard, meaning your evidence needs to clearly demonstrate that the assessed value exceeds fair market value. The Board issues a written decision within 45 days, and if they reduce your value, your tax bill is recalculated accordingly.

How much can I save by appealing my property taxes in King County?

On a typical King County home valued at $885,200 with an effective tax rate of 0.82%, even a 10% reduction in assessed value would save approximately $726 annually in property taxes. That reduction typically carries forward until the next reassessment, so one successful appeal can save $2,000 to $4,000 over several years. According to King County data, approximately 25% of property tax appeals result in some type of reduction, though the amount varies significantly based on the strength of evidence presented. The appeal process is free to file, and most homeowners spend 3 to 6 hours preparing plus 15 to 30 minutes at a virtual hearing, making it worthwhile for properties with legitimate over-assessments.

What evidence do I need for a King County property tax appeal?

The strongest evidence for a King County property tax appeal is comparable sales of similar homes that sold near January 1 of the assessment year for less than your assessed value. The Board of Equalization looks for homes with similar size, age, condition, and location that closed in the 12 months leading up to January 1. You should also include documentation of property condition issues such as photos, contractor repair estimates, and inspection reports that demonstrate factors affecting your home's market value. The Assessor's records should be checked for errors in square footage, bedroom/bathroom count, or other characteristics. Professional appraisals can strengthen your case, though comparable sales analysis is often sufficient for residential appeals.

Do I have to pay my property taxes while my appeal is pending in King County?

Yes, you must pay your property taxes by the regular deadlines (April 30 for the first half and October 31 for the second half) even while your appeal is pending to avoid interest and penalties. Paying your taxes does not waive your right to appeal. If your appeal succeeds after you have paid, King County will apply the overpayment as a credit to your next tax bill or issue a refund if your full year's taxes have already been paid. The Treasurer's Office will send a revised tax statement if the Board's decision occurs before the payment deadlines, or process a refund if the decision comes after you've already paid in full.

Can I appeal to the Washington State Board of Tax Appeals if I disagree with the King County Board of Equalization decision?

Yes, if you disagree with the King County Board of Equalization decision, you can file an appeal with the Washington State Board of Tax Appeals within 30 days of the mailing date of the Board's decision. This is a more formal process with stricter evidence rules, sometimes involving a written record instead of an in-person hearing, and more weight given to professional appraisals. For a $50,000 reduction dispute, representing yourself at the State Board level is reasonable, but for commercial property or larger disputes (such as $500,000), you should consider hiring an attorney or licensed appraiser. The State Board appeal preserves your rights to continue challenging the assessment if the county-level decision was unsatisfactory.

Official Resources

King County Assessor Website →

Official King County Assessor site with property value information, tax relief programs, and assessment details.

King County eAppeals Portal →

Online portal to file, track, and manage your property tax appeal electronically.

King County Board of Equalization →

Information about the appeal process, hearing procedures, and required forms for property tax appeals.

Washington State Department of Revenue - Property Tax →

State-level property tax information including exemption programs, assessment ratios, and appeal procedures.

For state-wide appeal information including Washington's assessment ratio and deadlines, see our Washington Property Tax Appeal Guide →

Considering professional help with your appeal? Compare pricing, coverage, and pros/cons in our Best Property Tax Appeal Services (2026) or browse side-by-side service comparisons →

More Washington Counties

Chelan County (Wenatchee)Clark County (Vancouver)Island County (Oak Harbor)Kitsap County (Bremerton)Pierce County (Tacoma)Skagit County (Mount Vernon)

← All Washington property tax appeal info

Sources: https://kingcounty.gov/en/dept/assessor | https://kingcounty.gov/en/independents/governance-and-leadership/government-oversight/board-appeals-equalization/appeal-property-tax | https://www.appealdesk.com/appeals/washington/king | https://kingcountytaxappeal.com/guide | https://blue.kingcounty.gov/Assessor/eAppeals/ | https://kingcounty.gov/en/dept/assessor/buildings-and-property/property-taxes/tax-relief/senior-or-disabled-exemptions

Last verified: 2026-07-22