Dual Citizenship in the European Union: trends and analysis (2010-2020) Poland Renunciation requirement for acquisition of citizenship Portugal Romania Slovakia Slovenia No renunciation No renunciation No renunciation No renunciation required for any mode required for any mode required for any mode required for any mode of acquisition of of acquisition of of acquisition of of acquisition of citizenship citizenship citizenship citizenship A05 Birth in country (acquisition after birth) No renunciation A06 Ordinary naturalisation Renunciation (note: exceptions A22/ A24/A26) A07 Socialisation-based acquisition Renunciation A08 Spousal transfer Renunciation A09 Filial transfer n.a. A10 Adoption No renunciation A11 Transfer to other relatives n.a. A12 Transfer from former citizen No renunciation A13 Spousal extension n.a. A14 Filial extension No renunciation A15 Extension to other relatives n.a. A16 Reacquisition n.a. A17 Restricted citizenship rights n.a. A18 Citizenship of a specific country n.a. A19 Cultural affinity n.a. A20 Presumed citizens n.a. A21 Very long residence n.a. A22 Refugees No renunciation A23 stateless or unclear citizenship No renunciation A24 Special achievements No renunciation A25 Public service n.a. A26 Financial assets No renunciation A27 Other reasons n.a. Renunciation requirement for acquisition of citizenship No loss of citizenship upon ret/acq foreign citizenship No loss of citizenship upon ret/acq foreign citizenship No loss of citizenship upon ret/acq foreign citizenship No loss of citizenship upon ret/acq foreign citizenship L05 Acquisition of foreign citizenship Loss L06 Non-renunciation foreign citizenship (acquisition by birth) n.a. 24 RSCAS/GLOBALCIT-Comp. 2020/4 - © 2020 Author