This paper examines recent attempts to professionalize Danish public sector auditing by the establishment of a certification of public sector auditors known in Danish as Certificeret Offentlig Revisor (COR). The establishment of the COR-certification has led to a dispute over the public sector auditing jurisdiction between a coalition of public sector auditors and the professional bodies of the private sector auditors. The paper outlines the process that led to the decision to create the COR-certification, analyse the COR coalition’s attempt to build a network of support for its jurisdictional claim of expertise, and discusses the general implications of the case for the ongoing attempt to create a European certification of public sector auditors. *) Paper presented at the 5th EIASM International Conference on Accounting, Auditing & Management in Public Sector Reforms, Amsterdam September 3-5, 200