I am in the process of setting up an ecommerce site selling food products (non perishable) and trying to understand how I would account for and charge sales tax to my customer.

The scenario is that I live in CA, my supplier/dropshipper is in WA, and the customer (who places and pays for the goods on-line) could be in any state nationally.

At what point is Sales Tax charged (me in CA, the supplier in WA, or in the state that the goods were ordered, paid for and received in)?

Thanks for any feedback!