I live in the United Kingdom. I am starting a USA based clothing store. A United States dropship / fulfilment company based in California will print and ship to United States customers.

The fulfilment will be on an individual sale basis, so no storage of inventory. Do I need to collect and pay US sales tax for all states? Do I also need to pay UK Tax?

The fulfilment company collects California sales tax on all orders to California (7.5%), if I don't have "A California State" resale certificate.

Thank you