The right to receive a reversionary interest at some future time, upon fulfillment of contractually specified conditions. This clause allows a lease-owner, lessee or a nonparticipating partner to reserve the option to participate in a well after it has produced enough to pay the operators expenses of drilling and completing that well. This clause is typically used in farmout agreements to convert the overriding royalty interest of a lease-owner, lessee or nonparticipating partner into a working interest upon payout of the well. When the election to convert the overriding royalty to working interest takes place, it is known as a back-in after payout (BIAPO).