Article 6 addresses the application of Top-up Tax rules during corporate restructurings. It defines how the EUR 750 million threshold applies to group mergers and demergers. The article provides rules for entities joining or leaving an MNE Group, including the treatment of deferred tax attributes and historical carrying values. It also clarifies the treatment of transfers of assets and liabilities, specifically under 'Pillar Two Reorganisations', and outlines the status of Joint Ventures and Multi-Parented MNE Groups, ensuring tax continuity and preventing avoidance during significant structural changes in corporate groups.