As carbon taxes are set to extend in depth and scope it will be critical to follow them from policymaking to implementation. Just Carbon Transitions (JUSTCARBON) spotlights the role of legal expertise in translating carbon taxation ideals into action. Tax systems and national legal jurisdictions present significant challenges for policy makers intent on tackling both environmental concerns and redistributive goals through taxation. There is an urgent need to investigate the role of legal tax professional structure, authority, and expertise to draw out how competition and cooperation among experts shapes the effectiveness of taxes in bringing about just transitions. These experts are crucial to study because the justness of (carbon) tax policies extend beyond ‘the letter of the law’, to the enforcement and control systems that make them effective - systems designed and populated by tax professionals. The study draws on an interdisciplinary research agenda shared between scholars of public administration and the sociology of professions and expertise. Through a comparative study of tax professionals and policy processes in three European countries – Denmark, Norway, and France – the study will give new insights into the implementation and operation of these systems, and how they are part of changing national legal orders on tax. Overall, the project will tell us where tax professionals are positioned in national policy advisory systems, what ‘legal expertise’ means in practice to these experts and which norms guide their work. The project is designed to expand this interdisciplinary agenda by bridging sociological and political science communities. During the project I will train with leading scholars in international comparative research on expertise and public administration, from sociological and political science perspectives. My goals are to develop a more complete research profile and my potential to be a future research leader in these fields.