(a) Payment of interest—(1) Payment by institutions. Each insured depository institution shall pay interest to the Corporation on any underpayment of the institution's assessment.

(2) Payment by Corporation. The Corporation will pay interest on any overpayment by the institution of its assessment.

(3) Accrual of interest. (i) Interest on an amount owed to or by the Corporation for the underpayment or overpayment of an assessment shall accrue interest at the relevant interest rate.

(ii) Interest on an amount specified in paragraph (a)(3)(i) of this section shall begin to accrue on the day following the regular payment date, as provided for in § 327.3(b)(2), for the amount so overpaid or underpaid, provided, however, that interest shall not begin to accrue on any overpayment until the day following the date such overpayment was received by the Corporation. Interest shall continue to accrue through the date on which the overpayment or underpayment (together with any interest thereon) is discharged.

(iii) The relevant interest rate shall be redetermined for each quarterly assessment interval. A quarterly assessment interval begins on the day following a regular payment date, as specified in § 327.3(b)(2), and ends on the immediately following regular payment date.

(b) Interest rates. (1) The relevant interest rate for a quarterly assessment interval that includes the month of January, April, July, and October, respectively, is the coupon equivalent yield of the average discount rate set on the 3-month Treasury bill at the last auction held by the United States Treasury Department during the preceding December, March, June, and September, respectively.

(2) The relevant interest rate for a quarterly assessment interval will apply to any amounts overpaid or underpaid on the payment date immediately prior to the beginning of the quarterly assessment interval. The relevant interest rate will also apply to any amounts owed for previous overpayments or underpayments (including any interest thereon) that remain outstanding, after any adjustments to such overpayments or underpayments have been made thereon, at the end of the regular payment date immediately prior to the beginning of the quarterly assessment interval. Interest will be compounded daily.