I'm not sure how it works elsewhere, including the UK, but I believe here in the Netherlands, ordering from Aliexpress counts as importing, i.e. if you were to sell that on to others (like a drop-shipper),
you're the retailer, but if you just keep it for personal use, then that's at your own risk.
Edit: tried to find a source again, [1] is the closest I could find and at least is reliable (but in Dutch).
[1] https://www.consumentenbond.nl/online-kopen/bestellen-bij-bu...