King County Property Tax Appeal — Washington

Rob Hartley·Updated February 15, 2026

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, Everett, Auburn

Median Home

$885,200

Tax Rate

0.82%

Annual Tax

$7,292

Population

2,400,000

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

You have either until July 1st of the assessment year OR 60 days from the date printed on your valuation notice - whichever gives you more time. Valuation notices are typically mailed between May and November.

Property in King County, Washington — local tax assessment and appeal guide

How King County Assesses Property

100%of market value

Assessed by: King County Department of Assessments

Assessment cycle: annual

Notices typically mailed: May through November

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 $7,259 in annual taxes at the county's effective rate of 0.82%.

The Appeal Process

Appeals are heard by the County Board of Equalization. The Board of Equalization schedules hearings based on appeal volume and filing date, typically notifying you 45 days in advance. You can request an expedited hearing or reschedule within 7 business days of receiving your notice.

Contact the Department of Assessments at(206) 296-7300 or assessor.info@https://kingcounty.gov before filing to discuss your concerns and potentially resolve without formal appeal

Gather evidence including comparable sales from near January 1 of the assessment year, photos of property condition issues, contractor repair estimates, or professional appraisals

File your petition online through eAppeals or by mail within 60 days of your valuation notice or by July 1, including specific reasons why the assessed value is incorrect

Submit all evidence to both the Board and Assessor at least 21 business days before your scheduled hearing date

Attend your hearing before the King County Board of Equalization, where you'll present your evidence and the Assessor will present theirs - decisions are issued within 45 days

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

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

Filing Methods

online:File through King County eAppeals portal - 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 1Professional 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: 201 South Jackson Street, Room 708, Seattle, WA 98104

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

Online Portal: https://kingcounty.gov/en/dept/assessor/buildings-and-property/property-value-and-information/appealing-a-valuation/file-appeal-online

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

Tax Exemptions in King County

Senior Citizen Property Tax Exemption

30-90% reduction based on income

Reduces property taxes by 30-90% depending on income level by freezing the assessed value

Eligibility: Age 61+ by December 31 of application year, own and occupy home 9+ months/year, household income under $84,000Deadline: No specific deadline - apply anytime online

Disabled Person Property Tax Exemption

30-90% reduction based on income

Same benefits as senior exemption for those retired due to disability

Eligibility: Retired due to physical disability, own and occupy home 9+ months/year, household income under $84,000Deadline: No specific deadline - apply anytime online

Disabled Veteran Property Tax Exemption

30-90% reduction based on income

Property tax reduction for veterans with service-connected disabilities

Eligibility: Veteran with 80%+ service-connected disability rating or total disability rating, income under $84,000Deadline: No specific deadline - apply anytime online

Official Resources

King County Board of Appeals and Equalization →

Official site for filing appeals and accessing forms for challenging your property tax assessment

King County Department of Assessments →

Main assessor website with property lookup tools, valuation information, and exemption applications

King County eAppeals Portal →

Online portal to file and track your property tax appeal electronically

Senior Property Tax Exemption Application →

Online application portal for senior citizens and disabled persons seeking property tax relief

King County Appeal Statistics

Success Rate

25%

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Frequently Asked Questions

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

The deadline to appeal your property tax assessment in King County is either July 1st of the assessment year OR 60 days from the mailing date printed on your valuation notice - whichever is later. Since valuation notices are mailed between May and November, many homeowners have until well after July 1st to file their appeal. It's crucial to check the mailing date on your specific notice and mark your calendar, as missing this deadline means you cannot appeal until the following year.

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

King County offers an online appeal system called eAppeals that allows you to file, track, and update your petition throughout the process. To file online, visit the King County eAppeals portal, enter your property address or parcel number, state your opinion of the property's value, upload supporting documents like comparable sales or repair estimates, and submit your petition. The online system is recommended over mail filing as it processes faster and allows you to instantly view appeal-related documents from both the Board of Equalization and the Assessor's office.

What is the senior property tax exemption worth in King County?

The senior property tax exemption in King County can reduce your property taxes by 30% to 90%, depending on your income level, with eligibility for those 61 or older who own and occupy their home at least 9 months per year and have household income under $84,000. This exemption works by freezing your property's assessed value, meaning you pay taxes on either the frozen value or current market value, whichever is lower. With King County's median annual tax bill at $7,292, this exemption could save eligible seniors thousands of dollars annually, making it one of the most valuable tax relief programs available.

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

At a King County Board of Equalization hearing, you'll present evidence supporting your claim that the property's assessed value is incorrect, while the Assessor's office presents their evidence defending the valuation. The hearing is scheduled about 45 days in advance, and both parties must submit evidence at least 21 business days before the hearing date. During the hearing, you can present comparable sales, appraisals, photos of property condition issues, or other market-based evidence, and the Board will issue a written decision within 45 days determining whether to adjust your property's value.

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

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. With King County's median home valued at $885,200 and an effective tax rate of 0.82%, even a modest 10% reduction in assessed value could save approximately $726 annually. Success depends heavily on providing compelling market-based evidence such as comparable sales from near January 1 of the assessment year, professional appraisals, or documentation of property condition issues that affect market value.

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

For a successful King County property tax appeal, you'll need market-based evidence proving your property is overvalued, with the most effective being comparable sales of similar properties from October through December before the January 1 assessment date. Other strong evidence includes professional appraisals dated near January 1, photos documenting property condition issues or deferred maintenance, contractor bids or repair estimates showing needed work, and documentation of factors like easements, slopes, or traffic noise that reduce market value. The Property Tax Advisor's Office at(206) 477-1060 can help you find comparable sales and understand what evidence will be most compelling for your specific situation.

Can I still 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 first half, October 31 for second half) even while your appeal is pending to avoid interest and penalties. If your appeal is successful and results in a reduced assessment, the King County Treasurer's Office will either send a revised tax statement if the decision occurs before April 30 or October 31, or issue a refund if you've already paid the full year's taxes. This refund process typically takes a couple of months to complete after the Board's decision, so it's important to pay on time regardless of your pending appeal.

What is the difference between assessed value and market value in King County?

In King County, assessed value and market value should theoretically be the same since Washington uses a 100% assessment ratio, meaning properties are assessed at their full market value as of January 1 each year. However, in King County's rapidly changing real estate market, assessed values often lag behind actual market conditions, sometimes undershooting or overshooting current values significantly. This discrepancy is why property tax appeals exist - if you can prove through comparable sales or other evidence that your assessed value exceeds what your property would actually sell for, you may be able to get your assessment reduced.

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

Clark County (Vancouver)Pierce County (Tacoma)Snohomish County (Everett)

← All Washington property tax appeal info

Sources: https://kingcounty.gov/en/independents/governance-and-leadership/government-oversight/board-appeals-equalization/appeal-property-tax | https://smartasset.com/taxes/king-county-washington-property-tax-calculator | https://kingcounty.gov/en/dept/assessor | https://kingcounty.gov/en/dept/assessor/buildings-and-property/property-taxes/tax-relief/senior-or-disabled-exemptions

Last verified: 2026-02-15