This paper provides an overview of the evolution of the harmonization process of European law in the field of group of companies, referring to the development of a national “group of companies law” — from the company law reform to the crisis and insolvency code — with the purpose of examining the main aspects of the regulation in force, considering mainly the possible interaction with the rules on the crisis of the groups of companies introduced by the Legislative Decree No. 14/2019, and with the aim of analyzing its suitability for being devoted to the prospect of harmonization across countries.