Enrichment without Couse

“Enrichment Without Couse” is a lawful rule based on forbiddance of asset transfer without cause of Enrichment. Thus, if a person takes action to pay it due to supposition for existence of a debt, and it is clear that there has been no such a debt, transferred asset will be committed to restore it by documenting the given rule, without legal reason and owner. But Iranian civil act has not stipulated this rule as one of the most important sources of commitment, it suffices to state some evidence of it like wrong fulfillment, other’s properties governance and fulfillment. So, in this inquiry, it has tried by finding legitimate documentations of the rule such as ayahs, hadiths, and Fighh evidences, existence and legitimacy of it is proved in Islam law, especially Imamieh Fighh that from this path, necessity of establishing rule and regulation of its regulations has been clear and arrangements to solve problems due to legal gap is provided.