The article offers an overview of the modernization of the European Commission (EC) accounting system. It represents an integral part of an overall rationalization of the EC organizational, administrative and financial dimensions which has been carried out over the last decade. The reformed accounting system is a dual one: it is based both on cash accounting, to manage budget appropriations, and on accrual accounting, to draw up the financial statements. Seventeen accounting rules, which draw upon International Public Sector Accounting Standards (IPSAS) and are based on accrual accounting, were issued by the EC and are the foundation of this reformed system. Drawing on semi-structured interviews with Commission officials, this article tracks the key turning points, trajectories and outcomes of events within the implementation stage of this part of the EC accounting reform with a focus on the consolidation of annual accounts. The compilation of the consolidated financial statement (CFS) has become more complex. The original European Union (EU) organizational structure (Parliament, Council, Commission, Court of Justice and Court of Auditors) has broadened with the addition of agencies that were created during the early 1990s. Since 2005, these agencies have been included in the CFS of the EU, compiled according to IPSASs 6, 7 and 8. This article examines how the EU consolidation process has evolved over time and the drivers behind the reformed accounting systems and in particular the new consolidation approach, which is a result of the combination of the Continental and Anglo-Saxon governmental accounting approaches.