MJ is right, you can be assessed on the VAT value anywhere in the EU and be forced to pay if you have no proof of VAT paid on import to the UK. My personal chariot dates from before the days of VAT, but every aircraft I fly for work carries the VAT invoice for purchase in the ship's papers.
I dread to think how many times I've been asked for that document in France and Belgium. They seem keener on VAT than whether my flight is legal public transport with AOC certificates and everything else in order, including a valid licence.
I'm not sure if it can still happen, but a few years ago the French would cheerfully assess your aircraft for VAT and demand payment, and hold the aircraft until the mess was sorted out, and my company credit card won't cover the VAT on a £20 000 000 aircraft!
SND