29 CFR 2702.8 - Advance payment of fees; interest; debt collection procedures.
(a) Advance payment of fees generally will not be required. However, an advance payment (before work is commenced or continued on a request) may be required if the charges are likely to exceed $250.
(b) Requesters who have previously failed to pay a fee charged in timely fashion (i.e., within 30 days of the date of billing) may be required first to pay that amount plus any applicable interest (or demonstrate that the fee has been paid) and then make an advance payment of the full amount of the estimated fee before the new or pending request is processed.
(c) Interest charges may be assessed on any unpaid bill starting on the 31st day following the day on which the billing was sent at the rate presecribed in 31 U.S.C. 3717 and will accrue from the date of billing.
(d) The Debt Collection Act of 1982, Pub. L. 97-365, including disclosure to consumer credit reporting agencies and the use of collection agencies will be utilized to encourage payment where appropriate.