Validity of Contract

Abstract This chapter examines the concept of validity in international commercial contracts, focusing on how the CISG and PICC address defects in consent and contracts infringing mandatory rules. It explores the limits of party autonomy in light of illegality, immorality, mistake, fraud, misrepresentation, duress, threats, excessive benefits, and unfair advantages. The chapter explains the CISG’s exclusion of validity questions from its scope, except where implicitly regulated, and contrasts this with the PICC’s detailed provisions on mandatory rules and defects of consent. It analyses the effects of invalidity, including rescission, adaptation, and damages, and highlights how these remedies aim to balance the protection of free consent with commercial certainty.