If any vehicle or aircraft is imported into any part of the United Kingdom other than the Isle of Man and the importer satisfies the Commissioners that—
(a) his principal place of business is outside the United Kingdom,
(b) the vehicle or aircraft is registered outside the United Kingdom,
(c) the vehicle or aircraft is owned and operated by a person whose principal place of business is outside the United Kingdom,
(d) the importation is taking place in the course of a journey which has begun and will end outside the United Kingdom,
(e) the purpose of the journey is to use the vehicle or aircraft either—
(i) for the transport of passengers for remuneration or for the industrial or commercial transport of goods from or to a place outside the United Kingdom, or
(ii) for such other purpose as the Commissioners may in special circumstances allow, and
(f) the following provisions of this Part of these Regulations, and such other conditions as may be imposed by the Commissioners, are and will be complied with,
such vehicle or aircraft may be delivered without payment of duty, and duty shall not be payable so long as the Commissioners continue to be so satisfied:
Provided that no vehicle or aircraft may be so delivered without payment of duty if the vehicle or aircraft is principally kept in the United Kingdom or if the importer principally keeps in the United Kingdom any vehicle or aircraft so delivered.