substitution of the obligation

The promisor, in fulfilling his /her obligation, can deliver a property rather than the object of the obligation to the promisee with his /her consent, hereby the obligation would be fulfilled and he would be discharged. This institution is called "dation in payment" which is distinguished from "substitution of the obligation". There is no provision regarding the conditions, nature and rules of this legal institution in Iranian Civil Code. In contrast, there are many discussions in French law and Common Law system in this regard. In the present paper, it is attempted to investigate the condition of realization, legal nature, rules and effects of this institution in Iranian legal system and Islamic jurisprudence through a comparative study with French legal system and Common Law. The result of the study demonstrates that the intention to fulfill, agreement, transfer and delivering a property different from the object are the requirements for the realization of "dation in payment" that share the same nature of fulfilling the obligation. However, it is distinguished from the ordinary fulfillment of the obligation in terms of conditions, rules and effects and should be considered a specific form of the latter.