Thesis:

A Comparative Study of Contract Assignment in the Legal Systems of Iran and Common Law with Emphasis on Lease Contracts

Contract assignment refers to the simultaneous transfer of rights and obligations arising from a contract, whereby a third party replaces one of the parties to the contract and becomes responsible for fulfilling the obligations and enjoying the related rights. Therefore, the main criterion in this transfer is the existence or non-existence of rights and obligations arising from the contract, whether the contract is of an instantaneous nature or continuous. However, adherence to principles such as the relativity of contracts, good faith, and freedom of choice of the contracting party is considered essential within the framework of the principle of freedom of contract assignment. Since with the assignment of a contract, the contractual obligations are also transferred to the assignee, who is obliged to fulfill those obligations, in cases where the contract is personal in nature, its execution by someone other than the original party to the contract (even if they are their legal representative) may be impossible or unacceptable to the other party. In such circumstances, the assignment of the contract will be void. The assignment of the contract, as well as the transfer of related positions from the assignor to the assignee, causes the original party to exit their initial legal relationships, and new individuals are placed in the contractual position as their substitutes. In this context, the legal position of the contracting party, along with all rights and obligations, is transferred to one or more third parties. One of the most significant effects of the derivative transfer of lease contracts, similar to voluntary transfer, relates to the substitution of the buyer in this type of contract. This clearly indicates that the substitution of the buyer in the lease context, regarding the transfer or assignment of the right to receive rent, the right to rescind, and eviction, faces challenges and differing opinions in courts. Research indicates that in the legal system of England, with the derivative transfer of the lease contract to the buyer, they are obliged to accept the terms of the lease contract, while the seller's responsibilities remain intact. This research is conducted descriptively and analytically, examining various aspects of this topic.

Keywords: Keywords: Contractual obligations, contract assignment, effects of contract assignment, lease