Residents of certain states, U.S. Territories, and Canadian provinces that have a state or provincial sales tax rate of less than 3% are eligible to purchase goods in Washington without paying sales tax if they will take and use the goods outside the state.  BUT, sellers are not required to make these exempt sales, and no refund is available if the seller chooses to collect sales tax. According to CCH, this exemption is commonly used by residents of Oregon, Montana, and the province of Alberta, Canada.