For a chain transaction between three parties, attribute the transport under Article 36a, classify both legs — intra-Community supply, domestic supply, import or export — and test whether the simplified triangulation regime of Article 141 is available. With the registration duties that arise where that simplification cannot be applied.
In an ABC chain there are two supplies but only one cross-border movement. The zero rate for the intra-Community supply can therefore be attributed to only one of the two legs — and which one determines everything. If the intermediary arranges transport, it depends on the VAT number they communicate: the departure country’s number shifts the intra-Community supply to the second leg, any other number leaves it with the first. That choice is no administrative formality.
The triangulation simplification then spares the intermediary a registration in the arrival country — but only if all five conditions are met. Drop one and the consequence shifts straight to a registration duty and a local return. The classifier works through the attribution, both legs, the five conditions and the registration risks in sequence and records the outcome with the legal basis, the tool version and the dataset vintage.