Anyone who settled in the country during the 1940–1991 German and Soviet occupations, and their children, did not automatically become Estonian citizens in 1991, and many of these first and second generation immigrants have remained in Estonia as noncitizen residents.

'Undefined citizenship' (Estonian: kodakondsuseta isik, Russian: негражданин) is a term used in Estonia to denote a post-Soviet form of statelessness.

[5] The policy meant a high level of statelessness initially, with almost 30% of the population having no citizenship in the first years after Estonia regained independence in 1991.

Human Rights Watch claims that this policy was discriminatory, especially against the country's Russian-speaking immigrant minority, and in violation of the International Convention on the Elimination of All Forms of Racial Discrimination.

In the 2010s Estonia took steps to reduce child statelessness, including granting citizenship to children born to non-citizen parents automatically.

[6] According to Peter Van Elsuwege, a scholar in European law at Ghent University, a number of historic precedents support this, most notably the case of Alsace-Lorraine when France on recovering the territory in 1918 did not automatically grant French citizenship to German settlers despite Germany having annexed the territory 47 years earlier in 1871.

[9] The European Commission against Racism and Intolerance, Advisory Committee on the Framework Convention for the Protection of National Minorities and UN Special Rapporteur on racism Doudou Diène recommend to Estonia simplifying naturalization generally or for the elderly and economically marginalized, as well as encouraging registration of children born in Estonia after 1991 as its citizens.

The QNI considers, in addition, to travel freedom on internal factors such as peace & stability, economic strength, and human development as well.