The subject of this article is the analysis of reasons and results of determining as well as changing tax residence in the light of Polish personal income tax. This topic underlies a broad concept of migration, especially that of profit-driven character. The author presents this research issue on the basis of the current legislation, doctrine as well as practice of applying the law by the judiciary and the tax autho-rities. The analysis of the valid regulations of tax law leads to the conclusion that the fiscal situation of migrants is so diversified as well as complicated from the legal point of view that it raises justified practical doubts. It is assumed that tax residence is dynamic and thus may change as a result of both intended and unin-tended taxpayers’ actions which may have specific tax law effects. They are reflected not only in tax preferences but also in obligations concerning tax settlements. Apart from ordinary tax consequences of determining or changing tax residence, the author relates also to particular legal solutions such as: exit tax, taxation of foreign controlled companies or appliance of the provisions of Multilateral Convention (MLI). The described issues are significant for both theory and practice of tax law application.