MERCER ISLAND Sales Tax Overview
As of 2026, MERCER ISLAND, Washington has a combined sales tax rate of 10.3%. This rate includes the Washington state tax of 6.5% plus applicable county and local taxes.
This rate applies to most taxable goods and services purchased within the 98040 zip code area. Some items such as groceries, prescription drugs, and clothing may be exempt depending on Washington state law.
MERCER ISLAND Tax Examples
* Based on rate of 10.3%. Verify with your exact zip code.
MERCER ISLAND Zip Codes & Tax Rates
| Zip Code | Combined |
|---|---|
| 98040 | 10.3% |
Frequently Asked Questions
What is the sales tax rate in MERCER ISLAND, WA?
The sales tax rate in MERCER ISLAND, WA is 10.3% as of 2026. This includes the 6.5% Washington state tax plus any county and city taxes.
How many zip codes are in MERCER ISLAND, WA?
MERCER ISLAND, WA has 1 zip code in our database: 98040.
How much is sales tax on a $100 purchase in MERCER ISLAND?
On a $100 purchase in MERCER ISLAND, WA you would pay approximately $10.30 in sales tax at the average rate of 10.3%, for a total of $110.30.
Is MERCER ISLAND's sales tax rate higher than the Washington average?
Use our calculator to compare MERCER ISLAND's rate of 10.3% against other cities in Washington. Visit the Washington state page for the statewide average.