Party Autonomy and Freedom of Contract

Abstract This chapter examines the principles of party autonomy and freedom of contract in international commercial transactions, highlighting their implications for opting in and out of legal regimes, derogation, variation, and mandatory rules. It analyses how parties may incorporate or exclude the CISG, PICC, and other instruments, addressing issues of express and implied exclusion and the interplay with mandatory domestic provisions. The chapter further explores the extent to which parties can modify or derogate from default rules and the limits imposed by mandatory norms. Finally, it discusses the principle of freedom of form, including the role of agreed formal requirements, no oral modification clauses, and the impact of electronic communications, illustrating how party autonomy shapes contractual formation, modification, and performance in international trade.