Simplifications: installed and assembled goods: background
Goods that are installed or assembled by the supplier are treated as supplied in the Member State of installation or assembly. This can make the supplier potentially registerable in any Member State in which they make supplies of this nature. For more details about this see the manual covering the place of supply of goods (VATPOSG).
The UK (along with some other Member States) operates simplification arrangements for suppliers of installed or assembled goods who are not normally present here. This is intended to reduce the need for their having to register for UK VAT. Details of any similar arrangements that may apply in other Member States should be obtained from the tax authority concerned. Contact details are available from the website referred to at VATSM1100.