In no case does the resident permit provide access to any type of employment. Employment, according to paragraph 6, article 20, of Law 4251/2014, does not include the exercise of economic activity in the capacity of a shareholder or a chief executive officer for an already existing company. So in your case, the establishment branch does not meet the condition of an already existing company. In any case we are waiting for changes to the immigration law that could be very positive for the investors, as per the relevant minister's announcements.
