39 CFR 3006.304: Procedure for assessing and collecting fees.

(a) Advance payment may be required if the requester failed to pay previous bills in a timely fashion or when the fees are likely to exceed $250.

(1) Where the requester has previously failed to pay within 30 days of the billing date, the Commission may require the requester to pay an advance payment of the estimated fee together with either the past due fees (plus applicable interest) or proof that the past fees were paid.

(2) When advance payment is required, the administrative time limits prescribed in 5 U.S.C. 552(a)(6) (§ 3006.201) begin only after such payment has been received.

(b) Interest at the rate published by the Secretary of the Treasury as prescribed in 31 U.S.C. 3717 will be charged on unpaid fee bills starting on the 31st day after the bill was sent. Receipt of a fee by the Commission, whether processed or not, will stay the accrual of interest.