The status of “posted worker“ has an employee who is sent by his employer to carry out a service in another EU Member State on a temporary basis, in the context of a contract of services, an intra-group posting or a hiring out through a temporary agency.
No doubts on how to properly post in Italy and/or another country an EU-national in force of free movement of workers referred to in art. 45 of the Treaty on the Functioning of the European Union and developed by EU secondary legislation and the Case law of the Court of Justice.
BUT then what to do in the case of workers employed in an EU country WHO ARE NOT EU CITIZENS?
1) the simplest solution in the corporate world seems to rely on the Schengen rule 90/180-day: the non- EU nationals who hold a valid residence permit or visa issued in one Schengen State have the right to move freely within the Schengen area for business or tourism purposes for stays that do not exceed 90 days in any 180 day period (=quota of 90 days in Schengen, no return until 90 more days have passed outside Schengen),
(Schengen Area covers most of the EU countries, except Ireland and the countries that are soon to be part of the Schengen Area: Romania, Bulgaria, Cyprus, and Croatia. Although not members of the EU, countries like Norway, Iceland, Switzerland and Lichtenstein are also part of the Schengen zone.)
Thus, in the case of the posting of a non-EU worker in Italy, employed by a company in a Schengen country and therefore necessarily in possession of a valid permit of stay in that country, there will be no formalities to be fulfilled other than to comply with the 90-day posting rule in a 180-day period and in the sole case where the border stamp is not being placed or if not staying in the hotel, the simply declaration on presence within 8 days following the worker’s entrance to be done to the police station in Italy,
2) on the other hand, in the case of workers without a Schengen visa or who are to be posted for a period longer than 90 days (out of 180 days), their employers will have to comply with the procedure for obtaining a nulla-osta in Italy through application of “FORM M2 – Communication of entry of foreign workers” to be carried out on the website of the Ministry of the Interior (some guidance in Italian here) in base of art. 27, comma 1 lett. i, e comma 1 bis of D.Lgs. 286/98.