Washington property taxes (2026)

How Washington property taxes work

Washington property taxes are county-run under state oversight: county assessors value every property at 100% of true and fair market value, and county treasurers collect. There's no income tax here, so the property tax carries serious weight, tempered by a levy system that limits how fast most district revenues can grow.

Payments are simple and statewide: first half by April 30, second half by October 31. Miss April 30 and interest starts at 1% a month, with penalties stacking at June 1 (3%) and December 1 (8%).

Appeals are the tricky part, because the deadline floats with your county's mailing schedule: you petition the county Board of Equalization by the later of July 1 or a set number of days after your change-of-value notice mails — 30 days by default, up to 60 where the county has extended it (King County uses 60). Counties mail value notices anywhere from late spring to late fall, so effective deadlines are spread across the second half of the year.

Seniors and people with disabilities get one of the country's stronger relief programs: an income-tested exemption (age 61+, or retired on disability) that freezes value and exempts part of the levies, with income thresholds tied to each county's median income.

When payments are due

First half due April 30, second half October 31 — statewide. Late payments accrue 1% monthly interest, plus penalties June 1 and December 1.

How to appeal your assessment

The statewide rule: Petition your county Board of Equalization by the later of July 1 or 30 days after your value notice mails (up to 60 days in counties that extended it, including King County)

Counties mail change-of-value notices on their own schedules from late spring into fall, so your real deadline depends on your county and your mailing date — it's printed on the notice. Filing is free.

1. Watch for your change-of-value noticeIt shows the assessor's new 100%-of-market value and your petition deadline — the later of July 1 or 30 days (60 in some counties) after mailing.
2. Gather market evidenceSales of comparable homes around the assessment date are the core of a Washington appeal — the burden is on you to show the value is wrong.
3. File your petition by the deadlineFile the county's Board of Equalization petition form (free) before the date on your notice. Late petitions need good cause.
4. Attend your hearingThe board hears you and the assessor informally; bring your comparables and photos.
5. Escalate if neededBoard decisions can be appealed to the state Board of Tax Appeals.

County pages have the exact local deadlines, forms, and filing links.

Statewide exemptions

Reassessment

Assessors revalue property at 100% of market value on annual cycles, with periodic physical inspections. Change-of-value notices mail on county-specific schedules from late spring into fall.

Value notices (Change of value notice) usually mail in summer–fall (varies by county).

Common questions

When are property taxes due in Washington?

First half by April 30, second half by October 31 — statewide. After April 30, interest runs 1% a month, with a 3% penalty at June 1 and 8% at December 1 on what's still unpaid.

How do I appeal my Washington assessment?

Petition your county Board of Equalization — free — by the later of July 1 or 30 days after your change-of-value notice mails (60 days in King County and others that extended it). The deadline is printed on your notice; comparable sales win the hearing.

Why is my appeal deadline different from my friend's in the next county?

Counties mail value notices on their own schedules from late spring to late fall, and the deadline floats with the mailing — 30 or 60 days after, depending on the county. There is no single statewide appeal date.

What relief exists for seniors in Washington?

An income-tested exemption for homeowners 61+ (or retired on disability) that freezes taxable value and exempts part of the levies — thresholds tied to county median income — plus a deferral program that can postpone payment entirely.

Is my assessment supposed to match market value exactly?

Yes — Washington assesses at 100% of true and fair market value as of the assessment date. If your assessed value is higher than what your home would have sold for on that date, that's the case to bring.