The current regulatory context for the energy sector and in which Energy Communities operate is fragmented and unclear in most EU countries. Although some initiatives have existed in Northern Europe for some time, this concept is considered relatively new. Indeed, EU legislation has only recently recognised Energy Communities through EU Directives 2018/2001 and 2019/944. In the framework of the Erasmus+ EU project EU-NETs (Grant Number KA220-VET-62435110), this qualitative research gathered information regarding the current adaptability and applicability of directives within national legislation, together with the legal and administrative frameworks in Spain, Italy, and Greece. Desk research and semi-structured interviews with 20 key informants from Spain, Italy, and Greece were conducted. Cross-case analysis was focused on the regulatory framework for ECs, its structure, and the models of governance. The results showed that the process of harmonisation of renewable energy legislation has not yet been completed in Southern Europe, with notable differences in the degree of implementation between countries.