If a customer pays for merchandise with a credit card, tax applies in the same way it applies to other sales. You must collect and pay tax on the full selling price of the merchandise, regardless of any fees you may owe credit card companies (WAC 458-20-108).
My DOR and other online services will be down for maintenance from 5 p.m. PST Friday, January 17, 2025, to 8 a.m. PST Tuesday, January 21, 2025.