Increasing economic integration inevitably draws states to coordinate their tax policies, yet policymakers are eager to protect their autonomous 'tax sovereignty.' Cooperation and autonomy are balanced in transnational networks, especially the OECD, where state representatives, experts, and interest groups engage in continuous negotiation to develop nonbinding, or 'soft' global tax policy norms. While the merits of these norms have prompted much scholarly analysis, little is understood about the nature and significance of using networks to develop tax policy norms in this manner. This Article demonstrates how and why states use the unique soft governance structure of the OECD to develop global tax policy norms and achieve national tax policy goals, and explores some of the implications of this particular means of balancing the competing goals of international cooperation and national autonomy in a politically, socially, and economically globalized world.