Each contract consists of three main parts:

1. Parties to the contract
2. Subject of the contract
3. Legal relations of the contract

By virtue of Article 183 of Iranian Civil Code: "A contract consists of one or more persons undertaking to perform a work or an obligation for one or more persons."

The parties may be natural or legal persons. The subject of the contract must be clear and definite and the contractual relationship between the parties must be completely transparent. Legal relations include: obligations of the parties, duration, guarantee, amounts, etc. Necessary points must be considered in drawing up a contract. Terms of contract must not be against public order, laws of the country and good morals. In order to conclude a contract, the parties must have the capacity. They must guarantee its implementation (sanction), and if a contract does not have a sanction, it is useless. The contract must be drawn up in an explicit and concise fashion and its provisions must be free of unnecessary complications. The number of copies must be mentioned and every party must have a copy.