Hire-purchase is a mutual interest contract. Regarding its commutative nature, exchangeable items that are against each other are exchanged in contracting process, so if contract is null or is canceled for any reason according to the contract terms, in the way that transferring possession is impossible, relevant actions will be based on the contract if funds entitled monthly installments are determined in. Therefore, the current paper aims to comparatively study hire-purchase in Iranian and common law. Analytical-descriptive method is applied in the paper. The findings indicate the difference between hire-purchase in Iran and common law is that contract for common law is just utilized for movable properties; while in Iran law it is utilized for both movable and immovable properties. In England law, hire purchase is a specified contract. According to the England hire purchase law and consumer credit law in 1974, hire purchase is a contract in which leased goods are transferred from creditor to the credit receiver instead of using periodic payment. It happens only when the credit receiver fulfills the contract terms. In other words the hire purchase contract used in England law is a hire contract with tenants’ rights of possession, while it has not been explained in the Iranian law.