King County, WA Property Tax Appeal Deadline
In King County, you appeal your assessed value to the County Board of Equalization by July 1 of the assessment year, or within the window after your change-of-value notice was mailed if that is later. The exact deadline is printed on your value notice.
How to appeal your property value in King County
| Who decides | King County Board of Appeals and Equalization |
|---|---|
| Deadline | July 1 of the assessment year, or within the county's window (up to 60 days) after the value notice was mailed – whichever is later |
| What to include | A completed appeal petition and a copy of your value notice |
| Late appeals | Generally not accepted |
| Next step if denied | Washington State Board of Tax Appeals |
| Official King County link | https://kingcounty.gov/en/dept/assessor/buildings-and-property/property-value-and-information/appealing-a-valuation |
Common questions
What is the property tax appeal deadline in King County?
July 1 of the assessment year, or later if your change-of-value notice gives you a later date. Check the date printed on the notice.
Where do I file?
With the King County Board of Appeals and Equalization, using its appeal petition form or online portal.
What should I send?
The completed petition, a copy of your Notice of Value and any evidence such as recent comparable sales.
What if I disagree with the board's decision?
You can appeal to the Washington State Board of Tax Appeals.
Related
- King County, WA property tax rate
- Washington property tax overview
- Pierce County, WA property tax appeal deadline
- Clark County, WA property tax appeal deadline
Last reviewed October 31, 2026. Rules and links come from the official sources shown above. Deadlines can move when a date falls on a weekend or holiday, and your notice shows your exact date – always check it. This page is general information, not tax or legal advice.