For many emerging and developing economies, it is exceedingly difficult to constrain residents from evading tax liability on income from capital, whether earned domestically or abroad. Meanwhile, an international regime for combatting offshore tax evasion is emerging, and the form of the new regime will be established during a narrow window of opportunity over the next few years. If a uniform, multilateral automatic information exchange system is established, it would improve emerging countries’ ability to tax the offshore accounts of their residents and, perhaps more importantly, their capacity to collect information about and tax domestic-source income from capital. In contrast, a fragmented automatic information exchange regime likely would not benefit countries outside the developed economies. Interestingly, the concerns of emerging and developing economies regarding the contours of the new international regime substantially align with the concerns of multinational financial institutions. As a result, emerging countries may find that multinational financial institutions could be improbable allies in the battle over taxing offshore accounts. However, a governance structure for a uniform automatic information exchange regime that could be useful to emerging countries’ tax administrations will materialize only if the regime evolves along the line of international financial law, with the G-20 playing an agenda-setting role. This article explores the requisite governance structure and concludes by describing steps emerging countries may take in bilateral and multilateral settings to help create that structure.