Article 20 F1
Where this article applies—
(a)
the NI-EU supply is to be treated as the supply that involves the removal of the goods from or to Northern Ireland; and
(b)
all supplies made after the NI-EU supply are to be treated as supplied—
(i)
outside the United Kingdom in the case of goods removed or to be removed from Northern Ireland to a customer in a member State;
(ii)
within the United Kingdom in the case of goods removed or to be removed from a member State to a customer in Northern Ireland.