This research area examines tax issues arising in cross-border contexts and within the framework of European integration. 

In a globalised economy, each State retains its tax sovereignty. International tax law arises from the necessity to coordinate potentially conflicting taxing powers, prevent double taxation, and curtail base erosion and profit shifting (BEPS). 

Research focuses on several strategic areas: 

• taxation of multinational enterprise groups and transfer pricing; 
• the impact of tax variables on investment and financing decisions; 
• empirical analysis of profit shifting phenomena; 
• reporting obligations such as country-by-country reporting and their effects on corporate behaviour; 
• the evolution of supranational initiatives (BEPS, Inclusive Framework). 

On the European side, particular attention is devoted to VAT harmonisation, double taxation and double non-taxation in cross-border transactions, the challenges posed by the digital economy, and the implementation of the VAT in the Digital Age (ViDA) package. 

The research also addresses cooperative compliance models (such as the ETACA initiative), tax governance and sustainability, and the tax implications of cross-border wealth transfers. 

The overall objective is to develop both legal and empirical analyses that contribute to building tax systems that are fair, efficient, and aligned with the transformations of the global economy.