King County sales tax rate, Washington
Quick answer
Combined sales tax in King County runs 10.45% across the cities we cover, on top of Washington's 6.5% state rate. The county share is a separate line from any city or special-district increment, which is why two addresses in the same county can pay different totals.
Cities in King County
County share shown separately from the city and district layers.
| City | State | County | City + districts | Combined |
|---|---|---|---|---|
| Seattle | 6.5% | 1.4% | 2.55% | 10.45% |
Source: Washington State Department of Revenue · rates as published for 2026