The emergence of global tax governance was triggered by common tax problems, which are now still being faced by international society of nation-states. In the creation of this framework, international institutions have been playing a major role. One of these institutions is the World Bank (Bank). However, those who write about the virtues and vices of the main creators of the framework usually disregard the Bank. This article, therefore, argues that this disregard is not justified because the Bank has also been playing a prominent role. Since two informal decisions taken in the past have contributed to this position of the Bank, the article gives in addition to it answers to the following two related questions: whether these informal decisions of the Bank were legal and if so, what implications, if any, they have for the Bank’s legitimacy.