Curious. So imagine that an UK customer buys from abroad two items at the same time, one with a £100 price, and another with a £50 price.
Since the online order is above £135, the customer doesn't pay VAT at purchase time and waits to pay it at the border.
Then something happens, and the commerce can't deliver one of them, or can't deliver them at the same time because it runs out of stock and resupply time is long.
Can the commerce ship only one of the items or must retain the first item until second item availability? Must the commerce then register and charge VAT to the customer in a separate payment before shipping ?
What happens then when the customer receives only one of the items ? Must the customer pay import VAT at border because it hasn't been paid yet, or not because it's under £135 ?