If you are a registered business and you believe you have overpaid taxes, penalties, or interest, you may request a refund directly from the department by:
The following information must be included with your refund request:
Note: A refund or credit cannot be made if the overpayment was originally received more than four years before the start of the current calendar year.
Mail your request to:
Washington State Department of Revenue
PO Box 47476
Olympia, WA 98504-7476