This Decision clarifies the detailed rules for forming and operating a Tax Group under Articles 40, 41, and 42 of the Corporate Tax Law. It details the ownership and residency requirements for Parent and Subsidiary companies. It explains the treatment of pre-grouping transactions and tax losses, the application deadlines for forming or joining a group, rules for business restructuring within a group, and notification requirements upon a subsidiary leaving or the group ceasing. Note this Decision is repealed by MD 301 of 2024 for tax periods commencing on or after 1 January 2025.