It's an interesting, and obvious, move on from what I was saying - but I'd never thought of buying the fuel VAT free (or claiming it back).
We just used to fly the aircraft VAT free for rental (assuming we actually made it across the FIR) and had fuel drawback exactly as explained by IO540.
If the aircraft was (for round figures) £100 an hour plus VAT (so 117.50 an hour) and we flew it for the six hours planned, we paid £600 (not £705) - then we got the duty drawback which could be another 30 to 50 pounds (depending on how much fuel had been uplifted since its last FIR crossing, again as mentioned by IO540).
It used to save the students a heck of a lot of money, made NO difference to the school revenue and, was never criticised by HM Customs who were fully informed of our plans.
If the crew also bought duty free whilst in Ostend - that was another saving.
The landing fees were £2 sterling at EBOS for an "SEP". Curious to know what they are now.