The Argentine and the French civil codes have recently undergone substantial modifications to their contract law provisions. These novel statutes could serve as models for future B2B contract law reforms in Latin American jurisdictions and beyond, as former Argentine and French laws have done in the past. The authors offer a contribution that paves the way in that direction with a systematic comparative analysis. As a starting point, this article unveils the influence that the modern unified laws on contracts (UNIDROIT Principles on International Commercial Contracts (PICC) and United Nations Convention on Contracts for the International Sale of Goods of 1980 (CISG)) have in Argentina’s and France’s new contract law. It also highlights the most obvious similarities and differences in both sets of rules. This contribution goes beyond simple tertium comparisons; the authors analyse which of the two laws offers better, or more effective, rules to achieve the desired contract law functions in various matters. Readers are provided with the best rule or solution to address the problem in question and, as the authors hope, they should conclude that both models provide for a range of complementary solutions for modern contract law reforms.