In 2007, official population information has started to be provided through the Address Based Registration System (ADNKS), instead of population censuses, thus resulting in a differentiation in the public administration and public services. In this article, first the concept of citizenship and the transformation of the citizenship regime of Turkey associated with population information gathering practices will be discussed. With an aim to reveal the change in the population information system, population data gathering activities, starting from the Ottoman Period, will be discussed. Then, how the structural transformation of the population of Turkey during the Republican Period and the need for the updated population data have been reflected in the data gathering system will be revealed. Finally, the factual effects of the shift from de facto system to de jure system for some selected public administration and public services are presented.