Invalidity of the amendment contract

Abstract

Invalidity is a basic legal institution of civil law; there are only few areas of civil law which are not affected by invalidity rules. In this study, the problematic of invalidity will be narrowed to a certain legal transaction, the contract amendment. After reviewing the potential connection points between the invalidity and the amendment of contract, the validity and invalidity of contract amendment will be comprehensively examined in order to answer the question, how the grounds of invalidity prevail in case of an agreement amending the contract. The problematic of illegal (or prohibited) contract will also be discussed regarding the case ‘substantial modification of public procurement contract’ regulated by the public procurement rules.