An istisna’a contract in which one counterparty (the seller or the buyer) is also a counterparty to a previous istisna’a contract as a buyer or seller, respectively. For example, the seller in an istisna’a contract may enter into a reverse istisna’a whereby he takes on the role of the buyer- i.e., by virtue of the new contract he agrees to buy from a third-party seller the same underlying asset of the original istisna’a. In the same token, the buyer in an istisna’a contract may seek a reverse istisna’a in which he assumes the role of the seller, agreeing to sell to a third-party buyer the same asset subject matter of the first istisna’a contract. In this sense, istisna’a, in its two forms, provides a viable substitute for debt financing, provided that the two contracts (the original and the parallel) are not linked or made contingent upon each other.

It is of crucial importance that delivery for the second contract takes place at a date farther than the delivery date for the first contract.

The reverse istisna’a is also known as a parallel istisna’a (parallel commissioned manufacture) or a back-to-back istisna’a.