The Analysis of Validity of Supplementary Conditions (addendum) to the Contract, in Iranian Law and Imāmiyya Fiqh

The issue of possibility of adding a supplementary condition to the contract has been considered by jurists from the ancients to the later ones, as well as Iranian lawyers. However, disagreement exists. It seems that this is rooted in the differences between experts' opinions regarding the condition and the quality of this credential creation. Therefore, it is necessary to collect important ideas to introduce a new classification of these topics to reach a better understanding of the issue. Accordingly, this Article, using a descriptive-analytical method, examines the sources collected from studying the opinions of the supporters and opponents of adding a condition to the contract then categorizes the opinions of the experts from both groups and also expresses the criteria adopted by the authors about the connection between condition and contract. So, it is concluded that since the condition is an obligation linked to a contract, it can be added to a previously existing contract and as a result of this addition, it is considered binding. Also, since the condition is a credential nature, any interference in this creature is in the authority of the parties. Thus, those concluding the main contract are entitled to decide about supplementary conditions and contract scope.