One of the challenges of Iran's banking system is timely collection of bank facilities from customers. For various reasons, some of the recipients of the facilities default on the timely payment of their overdue debt and cause disturbances in the country's monetary system. In this regard, banks and credit institutions adhere to jurisprudence and legal foundations through tools such as redistribution, contract conversion or renewal and by dividing the contracts into partnership and exchange contracts, non-current claims are postponed. For this basis and considering that the legal solutions of deferment are actually a kind of transition from one contract to another contract that affects the way of calculating interest, it is necessary to answer the question of whether debt deferment in the banking system along with the collection of interest for the new period faces a legal and Shariah obstacle or not. The proven hypothesis of this research is that the postponement of bank arrears by receiving new interest in partnership and exchange contracts has no shari'a and legal problems.