§  0.468   Interest.

   Interest shall be charged those requesters who fail to pay the fees
   charged. The agency will begin assessing interest charges on the amount
   billed starting on the 31st day following the day on which the billing
   was sent. The date on which the payment is received by the agency will
   determine whether and how much interest is due. The interest shall be
   set at the rate prescribed in 31 U.S.C. 3717.