The international tax regime has developed for more than a hundred years. While it has been dominated by double tax treaties, more recently the OECD has brought forward various initiatives which add significant complexity to the regime. At the same time the strong position of the OECD and the non-inclusiveness of its decision-making bodies have caused dissatisfaction with the regime. The most recent initiative on a United Nations Framework Convention on International Tax Cooperation (UNFCITC) is the result of this policy rejection. Considering the advantages and disadvantages offered by plurilateral agreements, inspired by the WTO system, plurilateralism could prove to be very valuable to overcome existing flaws of the current regime. Indeed, the UNFCITC if designed carefully could help to overcome many weaknesses of the current international tax regime and become the most meaningful development of the century in international tax law.