Limitation on Interest Deduction: caps on net interest deductions tied to EBITDA and group ratio rules to prevent base erosion. Limitation on interest deduction links deductible net interest to an entity's economic activity measured by EBITDA through a Fixed Ratio Rule capping net interest deductions, a Group Ratio Rule allowing additional deductions based on the worldwide group's financial ratio, and Targeted Rules for sector-specific risks such as banking and insurance; jurisdictions may exempt sectors with no material risk or design tailored rules where risks exist, and some domestic statutes cap interest deductibility relative to EBITDA or related-party interest to address thin capitalisation.