The Washington State Department of Revenue does not authorize SEA Airport to submit requests for refunds of sales taxes paid during your stay in Washington State. The State of Washington recommends that you request refunds of erroneously paid sales taxes directly from the business for which you paid the sales tax. When purchasing items, we recommend that you inform the cashier that you are not a resident of the State of Washington, and they will be able to fill out the appropriate paperwork to remove that sales tax from the item that you are purchasing. This is the most convenient way to avoid erroneously paying sales taxes during your visit to Washington State. You can find more information on their website.
