How Washington property tax works, with a Seattle example

Who sets your property tax?

Two sides decide the bill. The county assessor values the property, and the county treasurer collects the tax (Department of Revenue). Every taxing district then sets a levy: the state school fund, the county, the city, the school district and special districts.

• Value. All property is valued at 100% of true and fair value, using sales of the property or similar properties within the past five years, and cost or income methods in some cases (RCW 84.40.030). Real property is assessed every year at its value on January 1 (RCW 84.40.020).
• Rate. The rate is the sum of all levies on your parcel, quoted per $1,000 of assessed value. It changes each year.

The formula is simple: assessed value ÷ 1,000 × total levy rate.

What limits the increase?

Washington does not cap how much your assessed value can rise. It limits the levies instead, in two ways.

• The 1% rule. The combined levies of the state and all taxing districts may not exceed 1% of true and fair value, unless voters approve more as the Constitution allows (RCW 84.52.050). Voter-approved levies, such as school bonds, are the usual exceptions.
• The limit factor. A district’s regular levy may grow each year by the limit factor, plus new construction (RCW 84.55.010). The limit factor is 101% or 100% plus inflation, whichever is lower, for districts with a population of 10,000 or more (RCW 84.55.005). This limits the district’s total revenue, not your own bill.

Because your bill is a share of what each district levies, your tax can rise when voters approve a new levy or when your home’s value rises faster than the others’. King County says voter-approved measures, not rising values, are mostly behind increases.

For the state school levy, RCW 84.52.065 sets $2.075355 per $1,000 for taxes collected in 2027. The 2026 rate book lists the state school levy at 2.24959 (1.46154 plus 0.78805).

Is there a homestead exemption?

Not a general one. The sources read here list relief for seniors, people with disabilities and certain veterans, plus deferrals. The senior and disabled exemption (RCW 84.36.381) requires that you:

• own and live in the home as your principal residence;
• are 61 or older on December 31 of the filing year, or retired because of a disability, or a veteran with a service-connected rating of 40% or more (or a total rating); surviving spouses qualify at 57;
• have a combined disposable income under the county’s income thresholds.

The thresholds depend on the county median income. King County’s:

As the statute now reads (it applies to taxes collected from 2027), someone at or below threshold 1 is exempt from regular levies on the greater of $80,000 or 80% of the home’s value. Between thresholds 1 and 2, the exemption is the greater of $70,000 or 45% of value, capped at $200,000. At or below threshold 3, the state school levy and excess levies are also exempt, and the valuation is frozen. A deferral lets you postpone taxes on up to 80% of your equity if you are 60 or older (RCW 84.38.030). Ask the King County Assessor (206-296-3920) which version applies to your claim.

When are taxes due, and how do I appeal?

Late taxes on a home with four or fewer units carry 9% a year interest from the delinquency date; the statute applies penalties to other property types (RCW 84.56.020). In an appeal, you petition the county Board of Equalization on a Department of Revenue form.

Example: the median home in Seattle

The King County Assessor reports a 2026 median assessed value of $833,000 for Seattle residences. At the 2026 rate for Seattle (levy code 0010) of 9.90845, the tax is $8,253.74. The same table shows $7,943.77 in 2025, when the median value was $864,000, so the tax rose 3.9% while the median value fell.

The consolidated line includes the state school levy (2.24959, or $1,873.91). Seattle’s total is about 0.99% of assessed value. Your rate depends on your levy code, and your bill on your own assessed value. For the Seattle picture, see the Seattle guide. For what you pay at closing, see closing costs in Washington and REET. Lenders often collect the tax monthly through an escrow account.