The concept European civil service is being used in two ways, depending on specific context: In the broadest sense of the term, European civil service means the persons working for a European public institution and in the narrow sense of the term, it means only the European officials, who are not invested with public authority. European officials’ legal framework is governed by principles of law, guiding ideas for their overall activity and mandatory rules for the interpretation of any legal text adopted by an institution or European body. These principles are, on one hand, common with other branches of Community law in general (e.g. the principle of subsidiarity, the principle of equality, non-discrimination) and, on the other hand, specific principles of European civil service regulation (e.g. public competition principle and the principle of dispersion territorial). The paper demonstrates that the general principle of subsidiarity is strongly applied and that there is a dispute between the regulation based on the idea of legal status and/or the contractual status of civil service. There are legal restrictions and specific liabilities for the personel working within EU institutions and the paperwork makes some improvements propositions.