On our website we sell both physical products "fishing supplies" and educational products "fishing classes". Obviously supplies being shipped are taxed at the appropriate predetermined rate. However today we ran into a tax-related issue where people from the state of California purchased classes they will be attending in Washington state. So we are now selling the service at no tax to the California residents but facilitating the service in Washington. Can anyone think of a way we can force our classes to have Washington state tax as we will always be performing this service locally. Any help would be much appreciated!