Comparative Study on " Unenforceability" in Iranian and French

Unenforceability (Inopposabilité) is a double sanction. Because this sanction combines in the same time “validity” and “nullity”، validity between the parties and nullity to third parties. Our law obtains this sanction from French law. Thus for an exact study، referring to original law is inevitable. In Iranian law there are sporadic instances of unenforceability. But sometimes unenforceability is misdiagnosis with similar concepts، and its instances are neglected in the texts. Also we need general principles to use in ambiguous and silent cases. Generally unenforceability is misdiagnosis with “inefectivity” and “relative nullity”. Current instances are in three branches: civil law، commercial law، and intellectual property rights. Also in these grounds we can obtain general principles: “the motive role in unenforceability”، “third party’s concept”، “type of legal act”، “situation of subsequent legal acts”، “subjectivity or objectivity” and “retroactivity”.