Multilateral and private sector organizations in international development and industrial policy have increasingly been investing into the governance of extractive industries in recent decades. This manifests in a series of accountability mechanisms through which implementing and financing institutions commit themselves to transnational minimum standards. However, mediating between these abstract standards and their concrete implementation proofs to be problematic. We trace this problem by investigating accountability mechanisms in practice. We show how mining companies and international development banks outsource their accountability obligations to third parties, and how these entities mediate between abstract standards and implementation. We argue that the implementation of standards is paradoxically undermined by the proliferation of these mediating entities; a finding we explain referring to studies on transnational bureaucratic rule. In this paper we first introduce our understanding of mediation as bureaucratic practice in an internationalized order of rule. We then show how the mining company AngloGold Ashanti and the International Finance Corporation externalize accountability through mediation.