Section 1206.510 - Nonpayment of fees(a) Requesters are advised that should they fail to pay the fees assessed, they may be charged interest on the amount billed starting on the 31st day following the day on which the billing was sent. Interest will be at the rate prescribed in 31 U.S.C. 3717 .(b)Applicability of Debt Collection Act of 1982 (Pub. L. 97-365 ) . Requesters are advised that if full payment is not received within 60 days after the billing was sent, the procedures of the Debt Collection Act may be invoked (14 CFR 1261.407-1261.409 ). These procedures include three written demand letters at not more than 30-day intervals, disclosure to a consumer reporting agency, and the use of a collection agency, where appropriate.