41 U.S.C. § 3507: Interest and penalties for certain overpayments

for the period beginning on the date the overpayment was made to the contractor and ending on the date the contractor repays the amount of the overpayment to the Federal Government; and at the current rate prescribed by the Secretary of the Treasury under section 6621 of the Internal Revenue Code of 1986 ( 26 U.S.C. 6621 ); and if the submission of the defective data was a knowing submission, for an additional amount equal to the amount of the overpayment. Any liability under this section of a contractor that submits cost or pricing data but refuses to submit the certification required by section 3502(b) of this title with respect to the cost or pricing data is not affected by the refusal to submit the certification.