Drop Shipping Tax?

[einsteinwebsolutions]

We have an ecommerce website that sells physical products. We are located in UK, Our supplier is located in China and our customers (vast majority) are located in the USA.

1) We receive the order from the customer via the website.
2) We pay the supplier who is located in China.
3) The supplier ships the product directly to the customer in USA.

Scenario 1/
The products ship directly from China to United States. We are just the middleman.
Will we need to pay tax or register for tax? we are registered as a sole trader.

Scenario 2/
The supplier ship from China to other countries in EU (not UK). The person in EU pays customs tax.
Will we need to pay tax or register for tax?

Any advise would be greatly appreciated.