48 CFR §13.401

1. (a)The fast payment procedure allows payment under limited conditions to a contractor prior to the Government's verification that supplies have been received and accepted. The procedure provides for payment for supplies based on the contractor's submission of an invoice that constitutes a certification that the contractor—
   1. (1)Has delivered the supplies to a post office, common carrier, or point of first receipt by the Government; and
   2. (2)Shall replace, repair, or correct supplies not received at destination, damaged in transit, or not conforming to purchase agreements.
2. (b)The contracting officer shall be primarily responsible for determining the amount of debts resulting from failure of contractors to properly replace, repair, or correct supplies lost, damaged, or not conforming to purchase requirements (see 32.602 and 32.603).