The Big MAC is Back: Comparative and International Issues on Material Adverse Change (MAC) Clause

712 Abstract MAC/MAE clauses are standard and boilerplate provisions, often found in Common Law jurisdictions, used in both domestic and international corporate and financial transactions. Over the years its development has been led by American and English courts in a continuous way. Therefore, revisions and updates are always emerging based on new case law, commentary from legal scholars, and feedback from practitioners. However, something that has been omitted by scholars is that MAC/MAE clauses are also highly used and drafted in Civil Law jurisdictions. The problem arises when the transplant is done directly and without drafting adaptations, creating interesting challenges. Civil Law countries use American and English case law to understand MAC/MAE clauses, which leads to many questions as to how to enforce these alien clauses alongside Civil Law traditional excuses such as force majeure or hardship (or even frustration of purpose), or considering other legal obstacles or mandatory law. This essay attempts to fill this gap and presents the latest advances on MAC/MAE clauses and highlights the main issues from comparative and international contract law.