General principles: the transport rule
The transport rule is intended to ensure that preference is granted only to originating goods by avoiding, as far as possible, situations in which the goods can be ‘manipulated’ or substituted while in transit to the EU.
This objective is clearly fulfilled when originating goods have been invoiced to a customer in the EU by an exporter in the preference country of origin and have been transported directly to that customer, arriving in the same ship/aircraft container into which they were loaded in the country of origin.
However, direct transport is not always possible. EC preference legislation recognises this but lays down conditions under which goods which travel via third countries may benefit from preference. In particular, they must not be released to free circulation or be entered to home use in the country of transit. Guidance on interpreting the direct transport conditions can be found at IPGN5400.