17 CFR § 143.3 - Interest, penalty charges, and administrative costs.
(a) The Commission will assess interest on unpaid claims. The rate of interest assessed shall be the rate of the current value of funds to the U.S. Treasury (i.e., the Treasury tax and loan account rate) as prescribed and published by the Secretary of the Treasury. The Commission will charge penalty fees of not more than 6 percent per year on any portion of a claim that is delinquent for more than 90 days. The Commission will also impose actual administrative costs to cover the processing and handling of delinquent claims.
(b) Interest on claims will be charged and will run from the date the notice of claim is mailed if the amount of the claim is not paid within 30 days from that date. Interest will be calculated only on the principal of the claim. The rate of interest charged is the rate in effect on the date from which interest begins to run. The rate will remain fixed for the duration of the indebtedness.
(c) The Commission may waive in whole or in part interest, penalty charges or administrative costs if it finds that:
(1) The debtor is unable to pay any significant sum within a reasonable period of time;
(2) Collection of interest or penalty charges jeopardizes collection of the principal of the claim; or
(3) It is in the best interests of the United States.
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