Think King County has valued your home too high? An appeal asks the county Board of Equalization to review that value, rather than the tax bill itself. File through King County eAppeals or on paper. First, check the mailing date on your property value notice to find your deadline.

King County property taxes at a glance

Typical home value
$859,900Middle value2020–2024
Average tax rate
$8.94Per $1,000 of county valueTaxes due in 2025
Total property value
$920 billionCountywide2026 tax year
Total property taxes
$8.4 billionCountywide2026 tax year

Your appeal deadline

The county sends a notice showing the value it put on your property. For a mailed notice, file by July 1 of the year being valued, or 60 days after the mailing date printed on the notice, whichever is later. Use the printed mailing date, rather than the day you opened the envelope.

If the filing deadline falls on a Saturday, Sunday, or holiday, Washington's rule allows filing or a postmark by the next business day.

If you get your notice online, use the date the county sends it or tells you it is available. Check that notification and ask the Board to confirm the deadline if it is unclear.

Don't wait for your tax bill. The value notice you receive in 2026 affects the taxes you pay in 2027. Use the 2026 notice to work out your appeal deadline. That deadline can pass before the 2027 bill arrives.

Already past the deadline? The Board can allow a late appeal only in certain situations set out in state rules. Contact it to explain what happened; do not assume a late appeal will be accepted.

How to file your appeal

  1. Use the form for homes and land

    The county calls this the real property petition. Other decisions, such as being turned down for tax relief, have separate forms.

  2. Fill in your details and the value

    Include your property's county ID, called its parcel number, along with your contact details, the county's value, the value you think is correct, your reasons, and your signature. Use a separate form for each property ID. If filing after July 1, include the value notice. Anyone representing you needs your signed permission.

  3. Submit online or on paper

    Use King County eAppeals, or send two copies of your paper documents to the Board at the address below. Keep the filing confirmation or proof of mailing.

Do not email your appeal form. The Board accepts forms through its online portal or on paper. The portal also lets you track your appeal and view documents.

Find your form on the county forms page. It also has separate forms for business equipment, special land-use tax programs, and tax relief decisions, listed as personal property, current use, and exemption appeals. For filing questions, call the Board at 206-477-3400.

Send two copies of paper documents to King County Board of Equalization, 516 Third Avenue, Room 1222, Seattle, WA 98104. Follow the current form's instructions and check that the postmark is on or before your deadline.

Has the county valued your home too high?

Washington generally uses 100% of what a property could sell for, called its market value, before any tax relief that applies. The usual date for deciding that value is January 1. Look at what your land and buildings were worth on that date, including their condition and sales of similar homes around that time.

Start with King County eReal Property, the county's property lookup tool. It shows the county's values, home details, tax rates, and past sales. Check that the listed features match your home. Then look at nearby sales of similar properties and any damage, repairs, or limits on how you can use the property that affect its value.

The Assessor is the county office that values properties. If your record has an error, contact the Assessor's office at 206-296-7300. The county updates values every year and physically inspects properties at least once every six years. Check the recorded details before filling out your appeal form.

How to show what your home was worth

Choose records that help explain the value you are asking for:

  • Sales of similar homes: nearby properties with similar land and buildings that sold close to the date the county is valuing your home.
  • Photos and repair estimates: records of damage or work the home needs.
  • A professional appraisal: an estimate of value backed by supporting information.
  • Limits on using the property: restrictions on building or other rights, such as an easement that lets someone else use part of your land.

Explain how each document supports the value you think is correct. A stack of sales listings without that explanation is harder to follow.

An example of explaining comparable sales

Illustration, not actual King County sales: Suppose two nearby homes sold for less than the county's value for your home. They are similar in size, age, and lot size, and sold close to January 1. One has a remodeled kitchen; yours still needs that work.

List each sale's address, date, price, and relevant features beside your home's details. Explain why the differences matter: the remodeled home may have sold for more than yours would have. Attach the sale records and photos showing your kitchen's condition on the valuation date.

Use those comparisons to explain the value you are requesting. Avoid simply subtracting a renovation quote from the county's value; explain how the condition affects what a buyer would pay.

A neighbor's lower county value, a large increase in your own value, or difficulty paying the bill does not prove what your property could sell for. Those reasons alone do not support a property-value appeal.

You can ask the Assessor for the information it used to value your home, including sales of similar properties. Ask early so you have time to understand the county's position and meet the deadlines for sharing documents.

What happens after filing

The Board sends hearing details for accepted appeals. This is the review where you can explain your case by phone, or choose to have the Board review your written documents without you taking part. Keep your appeal number.

You have a separate deadline for sending supporting documents. King County requires them at least 21 business days before the hearing, not counting weekends or legal holidays. Send new evidence to both the Assessor and the Board. For mailed evidence, the postmark is the date that counts. Follow the hearing instructions carefully.

If you disagree with the county Board's decision, you can ask the Washington State Board of Tax Appeals to review your property's value. File by the 30th day after the county Board mailed its decision. The state Board cannot extend that deadline. Find the state appeal instructions.

Keep paying your property taxes when due while you wait for a decision. A lower value may lead to a refund or credit, but filing an appeal does not change your payment deadlines.

Total property taxes rose about 10% for the 2026 tax year, while total property value rose 5.4%. Much of the tax increase came from voter-approved measures. A larger bill alone does not show that the county has valued your home too high.

These figures describe the whole county. The home value covers homes lived in by their owners during 2020–2024, rather than today's prices. Your home's value, tax rate, and change in taxes may be different. Check your own property record before deciding whether to appeal.

When notices and tax bills arrive

The county mails notices of changes to property values between May and November. The value shown on that notice is used for the next year's taxes.

Your yearly tax statement is mailed in mid-February. The county does not normally send a second statement before the fall payment. The usual payment dates are April 30 and October 31. If either falls on a weekend or county holiday, payment is due the next business day.

If your bill is $50 or more, you can pay in two halves as long as you pay the first half by April 30. Smaller bills are due in full by April 30. These payment dates are separate from your appeal deadline.

Other property tax relief

An appeal is not the only way to get help with property taxes. King County has tax relief programs for qualifying seniors and people with disabilities. Some reduce taxes, called exemptions; others let you delay payment, called deferrals. Check the current application requirements for the year involved.

Who to contact in King County

Your home's details and value

King County Assessor

206-296-7300
Assessor.info@kingcounty.gov

King Street Center
201 S. Jackson Street, 2nd floor
Seattle, WA 98104

Customer service: Monday–Friday, 8:30 a.m.–4:30 p.m.
Appeal forms and hearings

Board of Equalization

206-477-3400
boe@kingcounty.gov

516 Third Avenue, Room 1222
Seattle, WA 98104-2306

Include your appeal number or property's county ID when asking a question. Do not email your appeal form.

King County property tax appeal questions

Can I file my appeal online?

Yes. Use King County eAppeals. The Board also accepts paper appeal forms, but does not accept them by email.

Does a big jump in the county's value prove it is wrong?

No. An increase alone does not prove what your home could sell for. Use sales and other records that show what it was worth on the date the county is valuing it.

Do I have to attend a hearing?

You can participate by phone or request a review of your written materials without participating. Follow the Board's instructions for choosing the hearing format.

Do I still need to pay my tax bill?

Yes. Keep paying when taxes are due while the appeal is pending. A value reduction may lead to a refund or credit.

Official King County resources

Use these tools to look up your property, fill out the appeal form, and follow your case.

Look up your property record Check the county's value, your home's details, tax rates, and past sales.King County Assessor File and track your appeal online Send in your appeal through eAppeals and return to check your case and documents.King County eAppeals Appeal forms and permission to represent you Get the form for homes and land, or find the form for another type of appeal.King County Board of Equalization County filing and hearing instructions Check filing methods, the notice-date deadline, useful evidence, and hearing choices.King County Board of Equalization Tax bills and payment dates Read the Treasury's answers about statements and the spring and fall payment deadlines.King County Treasury Senior and disability tax relief Find out how to apply for programs that reduce taxes or let you delay payment.King County Assessor

Guide prepared by LowerTheTax.

Sources and data notes

We check filing instructions against the county Board of Equalization, current petition forms, and Washington rules. Where official pages use different wording, the current form and governing rule guide our explanation. Data years and sources are listed below. The comparable-sales example is an illustration, not a reviewed appraisal or a real appeal outcome.

Sources checked October 5, 2026. The typical home value is the median, or middle value, for homes lived in by their owners during 2020–2024. Half are above it and half are below it. It is not an average or today's sale price. The average tax rate is the county's 2025 levy rate per $1,000 of assessed value, rather than the rate for every property. County totals and increases do not describe every homeowner's bill. Use the current form and the instructions for your own notice and hearing.