The OECD and EU Commission are cracking down on patent box tax regimes that provide tax advantages for intellectual property income. They consider some current regimes to provide unfair tax benefits without requiring real economic activity in the granting country. Reforms are aimed at closing loopholes and increasing transparency, focusing on issues like substantial activities and nexus between the tax benefits, R&D expenditures, and income earned. This crackdown raises questions about whether European IP box regimes will still attract R&D companies and whether corporate tax arrangements will face more scrutiny in the future.