What USA shops charge USA sales tax?

My US partners all live in Oregon which does not have state sales tax so all orders placed via my service are USA sales tax free.

The only exception are orders that are shipped via Sea Freight which may incur Californian state sales tax (~10%) if the store has a physical presence in California. My US partners can often get the Californian sales tax back and if they do it will be refunded back to you. This claim-back process normally takes a few months - nothing to do with tax in the USA is fast or easy.