A Comparative study on the relationship between ‘fundamental non-performance’ and ‘Nachfrist’ requirements for termination of contract
Authors:   Korean Civil Law Association, Gwak Minhui 
Published: January 2025

The CISG-based cancellation structure, that is, in the case of cancellation, does not require attributable reasons, and the cancellation structure centered on the so-called “fundamental breach of contract” has been directly accepted in each country's revised laws. In particular, it can be seen in common that reasons attributable to major countries such as Germany, France, and Japan tend to be deleted from the recently revised laws. Instead, the acceptance of the requirements for “fundamental non-performance” is being considered, for example, in the revision of the German Civil Code, the concept of “fundamental non-performance” is recognized as an exception while expanding the scope of application to all contract violations in principle by canceling the set of the Nachfrist. The Japanese Civil Code also requires the concept of serious non-performance, albeit passive, through a minor defense, with the highest cancellation as a principle. It can also be understood in the same context that the French Civil Code requires the materiality and non-existence of non-compliance while acknowledging the avoidance of contract by the creditor's expression of intention other than the court's avoidance of contract. Regarding the introduction of the “fundamental non-performance” requirement, it is also approved by comparative law, and the revision of our civil law is expected to be introduced based on what has been discussed in practice. The problem is that in the case of introducing a “fundamental non-performance”, the relationship with the “Nachfrist” requirement, which has been previously required as a requirement for avoidance of contract, should be considered. The former originated in British-American law, and the latter originated from Nachfrist of German law, which is a heterogeneous requirement resulting from separate and independent legal systems. In response, the CISG recognizes the avoidance of contract of the “fundamental non-performance” and the setting of the “additional period of time” as “parallel” - respectively independent requirements for avoidance of contract, which are evaluated as a successful fusion of separate systems in comparative law. On the other hand, in German law or recently revised Japanese law, Nachfrist for avoidance of contract is a principle, and the concept of serious non-performance is passively accepted, and both are composed of coexistence requirements. In our 2013 amendment, fundamental non-performance, minor defense- and maximum have been constituted as practical and procedural requirements for avoidance of contract, respectively (Article 544 (1) and (2) of the 2013 Amendment). As the recent legislation of each country has different ways of accepting the two heterogeneous systems, it is necessary to review how to establish the relationship between these requirements in the discussion on the revision of our law. Until now, there has not been much active discussion on this point. This article examines the relationship between fundamental non-performance and Nachfrist for avoidance of contract from the perspective of historical and comparative law.