The contribution aims to analyse the effects of cross-border circulation of public documents under EU law (i.e. mere circulation of the instrumentum, exclusive to any recognition of the negotium), following a twofold approach based on legal methodology (i.e. EU free movement law and private international law techniques) and legal policy (i.e. EU integration and functionalism).The starting point of the analysis is the current contradiction/tension within the EU legal order between, on the one hand, the need to ensure the permanence of the personal status of individuals and families (such as family name, parentage or marital status) on the basis of EU citizenship (Arts. 18 to 21 TFEU) and, on the other hand, the limited scope and effects of the legal instruments in force in EU law, i.e. Regulation 2016/1191 on public documents, complemented by international conventions in force within all or some Member States, such as the HCCH Apostille Convention of 1961 and ICCS Convention (No 16).In this context, the article proposes to explain this contradiction, to assess it and finally to submit legal ways to overcome it, while considering the restraints of political feasibility. It provides for a cross-cutting analysis of the (above-mentioned) legal frameworks, complemented by relevant case law of the CJEU, of the ECtHR and of national courts of the Member States, under this specific perspective.