Recent debates about global justice have featured various proposals to make the world more just by means of transferring money. Their assumption is that just purposes may be achieved by applying, in a global context, the kind of redistributive fiscal policy that has proven capable of supporting social justice within the context of a welfare state. In global or international contexts, however, that assumption may not be warranted. In the absence of global political institutions and a single global currency, it would be premature to make policy commendations whose effectiveness would presuppose their existence. Additionally, there is a problem that the value of taxes, even if successfully raised and transmitted, can be subject to volatilities in financial markets. Attention should be directed to the institutional conditions required for global taxation as well as for the governance of global finance more generally to ensure it is in the public interest.