The phenomenon of citizenship as an integral part of the sovereignty of the state is considered at the level of universal international legal acts in general, and the Convention on Citizenship of the Commonwealth of Independent States (CIS) in particular.

In this study, the institution of citizenship as the basis of legal identity is justified as an important factor determining a person's legal identity and his connection with the state. Great importance is attached to the harmonization of laws with international standards. The article concludes that despite the progress made in the field of citizenship, there is still a need for legislation to protect the rights of migrants, prevent statelessness and ensure equal opportunities for all citizens.