According to the principle of contracts freedom, the principle of autonomy requires that the contract's parties can conclude the contract in any way they wish. And in
this way they are not obliged to choose the prefabricated forms in conditions, works, as well as the guarantee of the performance of the contracts. And they can include
any condition which they would in accordance with (Article 10 of the Iran Civil Code): Provided that it does not be against the law or contrary to the nature of the
contract. One of these conditions, which the parties are inserted while contracting with the aim of ensuring the implementation of commitments, is penalty clause
condition which is of great importance in jurisprudence and law of Iran.