Executive summaryOn 14 May 2020, the European Commission (the Commission) sent a letter of formal notice to Portugal requesting Portugal to adjust its internal law to be in line with the interest limitation rule set forth under the European Union (EU) Anti-Tax Avoidance Directive (ATAD) – Article 4 of the Council Directive (EU) 2016/1164.Detailed discussionThe ATAD was presented by the Commission as part of the Anti-Tax Avoidance package in January 2016, to provide a coordinated implementation across the EU of a specific set of anti-tax avoidance provisions, namely, interest deduction limitation rules, controlled foreign corporation rules, hybrid mismatches rules, exit taxation...