VATPOSG4200 - Supplies on board ships, aircraft and trains: international journeys
All supplies of goods during an international journey (that is a journey to and from a third country) are treated as taking place outside the UK and so are outside the scope of UK VAT. This includes goods which technically could be regarded as having been supplied within UK territorial limits at the start of a journey departing from the UK or at the end of a journey to the UK. An international journey commences once the means of transport has left the final place at which a domestic passenger can alight and vice versa for journeys ending in the UK.