Since the global financial crisis, international corporate taxation has risen to the top of the global political agenda, as political leaders have called for collective action to shore up corporate tax systems. However, high‐level political initiative alone does not create new international corporate tax rules. Rather, these transnational governance processes are centrally driven by elite tax professionals competing for prestige and influence. In this article, I investigate this competition in the case of one crucial post‐crisis reform – the OECD/G20 Base Erosion and Profit Shifting project. I argue that hierarchies of prestige and influence for elite professionals in transnational tax governance are based on strategic combinations of career resources in issue‐specific ‘linked ecologies'. In particular, I detail the expertise and network positioning of elite professionals, and discuss how these resources were mobilized in competitions for professional authority, which in turn shaped the transnational policy process. Evidence is drawn from qualitative interviews and career analysis.