Open Access

On 25 October 2016, the European Commission presented a proposal for a directive on a Common Corporate Tax Base (hereafter CCTB Proposal), which contains a comprehensive concept for the harmonisation of profit calculation regulations within the EU. Against this current background, the objective of the present work is to contribute to the implementation of the CCTB by identifying ambiguities and conceptual weaknesses in the design of the profit determination system of the CCTB Proposal and developing concrete recommendations for action for adjustments in the course of the further legislative procedure. In the first article, selected profit calculation rules of the CCTB Proposal will be analysed in detail and compared with the provisions on profit calculation under German commercial and tax law and the International Financial Reporting Standards (IFRS) recognised across member states. Based on the legal comparison, questions of interpretation and inadequacies of the profit calculation system will be considered and proposals for adjustments to various regulatory areas will be submitted. Furthermore, in the second article, within the framework of a holistic study, expert interviews will be used as an empirical-qualitative research design to generate reliable assessments on the part of the various stakeholder groups affected by the implementation of the future directive or involved in its elaboration. The results show the extent to which the profit determination rules of the CCTB Proposal in their current form are suitable for national and EU-wide implementation and in which areas the various expert groups still see concrete need for adaptation. Based on these expert assessments, the third article finally develops a proposal to reduce the threat of legal uncertainty in interpretation issues criticised by the experts. Based on economic maxims developed by the European Commission and existing accounting principles of the current CCTB Proposal, the EU Accounting Directive and IFRS, a system of specific European tax principles will be developed which could be implemented within the framework of the CCTB Proposal.