King County property tax appeals
Notices here are mailed when your assessed value changes. If you received one, your deadline runs from its date. You can file by July 1 or within your county's 30-day or 60-day notice period, whichever is later.
Appeals go to King County Board of Appeals and Equalization.
Washington values your home every year at 100 percent of market value, and you appeal to your county Board of Equalization. An appeal makes sense when recent comparable sales show your value is too high. It usually will not help if your bill rose only because the tax rate or levies went up.
- Recent comparable sales show your assessed value is above what your home would sell for.
- The assessor's record has an error in your home's size, condition, or features.
- You file on time: by July 1, or within 30 or 60 days of your value notice, whichever is later.
- Your bill went up but your assessed value is fair. A higher bill often comes from levies and the tax rate, not the assessment.
- You have no market evidence. The assessor's value is presumed correct, so you must show it is wrong.
Read the full explanation
In Washington, county assessors value your home every year at 100 percent of its true and fair market value. If you think that value is too high, you appeal to your county's Board of Equalization, not the assessor. The assessor's value is presumed correct, so you need market evidence, such as recent comparable sales, that the value is wrong. You usually file by July 1, or within 30 or 60 days of your value notice depending on the county, whichever is later. An appeal helps when you have real evidence the value is off. It will not help just because your tax bill went up, since a higher bill can come from levies and the tax rate, not your value. This is general information, not tax advice.
Source: Revised Code of Washington 84.40.030 and 84.40.038 · checked 2026-07-16. In Florida we run the numbers for you. In Washington we give you the deadline, where to file, and the rules, verified against official sources.
- Filing window:
- File by July 1, or within 60 days from the mailing date on your value notice, whichever is later. King County uses the 60-day window, and offers online eAppeals.
- Where to file:
- King County Board of Appeals and Equalization
- Phone:
- 206-477-3400
Verified against official sources, approved 2026-07-16.