How you can register for Union scheme
Under the Union scheme a taxable person can register in the Member State of Identification (place of business or of the permanent establishment). If the taxable person has more than one permanent establishment in the EU, it is entitled to choose only one Member State to be the Member State of identification.
Italy is your Member State of identification if, in the Italian territory, you have established your business or you have a permanent establishment or is the place of transport or dispatch of goods. To access the One Stop Shop for EU businesses you must be registered to Italian Revenue Agency online services (refer to the Italian version of the website).
In case Italy is the place of transport or dispatch of goods, you have to appoint tax representative in order to register to online services.