This Article addresses two related first- order questions about morality that enable us to discern solutions that address second- order questions in the specific policy context of regulation of tax competition and BEPS: (1) what kind of justice conception has sufficient normative support to undergird regulation attempts of this global phenomenon to ensure cosmopolitan tax rights? (the global tax justice question); and (2) what are the pre- conditions of effective cooperation, not based on immediate self- interest, that eschew a market- based approach to tax competition, enabling background conditions for the morality of multilateral cooperation? (the morality of cooperation question). The Article addresses the global tax justice question by discussing the Rawlsian premises to the concept of tax justice and its developments within the internationalist approach; the Article then shifts the focus on the cosmopolitan challenge to Rawls, which introduces, at least theoretically, the possibility of fundamental rights of global tax justice to then draw conclusions about three available normative options for the governance of tax competition and BEPS, which can be derived from the previous analysis.