[trocadero]

>It's not so much the tariffs as the customs clearance per se. Everyone seems to have forgotten that transporting goods across a border has VAT implications, and if you don't check and aren't part of the same VAT area there's a huge opportunity for "carousel fraud".

That would give the EU reason to block imports from the UK. It doesn't give much of a reason for the UK to block imports from the EU. So there's no reason to expect that the UK will starve or Amazon will shut down. The only way for that to happen is for the UK to shoot themselves in the foot (again).

Exports, of course, are a whole different story and that's where the risk lies. General economic damage from increased friction in exporting to the EU.

[NeedMoreTea]

They have to get through customs and multi-mile stacks on the M20 even when empty returning from a delivery. If half a EU company's drivers are stuck in the UK for a day or week longer than intended the chaos will quickly spread far beyond just affecting UK exports only.

Given modern approaches to warehousing and logistics (see how quickly KFC completely fell apart when changing chicken supplier recently) there will be shortages and probably issues with fresh produce. If there are some shortages, any shortages, panic buying and last minute stockpiling will commence. Then there will soon be real shortages.

[pjc50]

Even if the UK decides to accept fraud and have a customs-free border, shipping is bi-directional; once the tailbacks start, lorries start parking up on the M20. Drivers are going to be reluctant to cross the channel if they can't get back again in a timely fashion.

(Are EU truck licenses valid in the UK after Brexit? And vice versa? Who knows?)

[trocadero]

The issues you mentioned are relatively minor. Drivers will still cross if they are paid enough. The UK can easily recognize EU truck licenses on their own. Undoubtably Brexit will cause some disruption to UK/EU trade, but it's pretty far fetched that it will completely break down.