Article 36
Where goods dispatched or transported by the supplier, by the customer or by a third person are installed or assembled, with or without a trial run, by or on behalf of the supplier, the place of supply shall be deemed to be the place where the goods are installed or assembled. Where the installation or assembly is carried out in a Member State other than that of the supplier, the Member State within the territory of which the installation or assembly is carried out shall take the measures necessary to ensure that there is no double taxation in that Member State.