Rules of good faith and fair behavior in contracts; In Iranian jurisprudence and law with a comparative study of European Union law

backgroud and The principle of good faith and fair behavior is one of the important moral and legal principles. The purpose of this article is to examine the rules of good faith and fair behavior in contracts in Iranian jurisprudence and law and European Union law. This article is descriptive and analytical. The materials and data are also qualitative and data collection has been used.Ethical considerations: In this article, the originality of the texts, honesty and trustworthiness are observed. In the laws of the European Union, the principle of good faith and fair treatment is clearly stated. In Iran's legal system, the term "good faith" is not used in the civil law, but in laws such as the civil liability law approved in 1339 and the e-commerce law of 1382 and Iran's trade law, this term is implicitly used. In Shia jurisprudence, there are reasons that emphasize the necessity of honesty and correctness in contracts, including commercial contracts. In European Union law, good faith and fair dealing in contracts are explicitly recognized. The scope and function of good faith in Iran's law has been more prominent in the pre-contract periods and it is formed based on the will between the parties to the transaction and the intent to create contractual obligations. So that the issue of the functional domain of goodwill in Iranian law is related to intention