General rule. Except as otherwise provided, interest shall be allowed on any overpayment of any tax at the overpayment rate referred to in § 70.93 of this part from the date of overpayment of the tax.

Date of overpayment. Except as provided in section 6401(a) of the Internal Revenue Code, relating to assessment and collection after the expiration of the applicable period of limitation, there can be no overpayment of tax until the entire tax liability has been satisfied. Therefore, the dates of overpayment of any tax are the date of payment of the first amount which (when added to previous payments) is in excess of the tax liability (including any interest, addition to the tax, or additional amount) and the dates of payment of all amounts subsequently paid with respect to such tax liability.

Period for which interest is allowable in case of refunds. If an overpayment of tax is refunded, interest shall be allowed from the date of the overpayment to a date determined by the appropriate TTB officer which shall not be more than 30 days prior to the date of the refund check. The acceptance of a refund check shall not deprive the taxpayer of the right to make a claim for any additional overpayment and interest thereon, provided the claim is made within the applicable period of limitation. However, if a taxpayer does not accept a refund check, no additional interest on the amount of the overpayment included in such check shall be allowed.

Period for which interest allowable in case of credits—(1) General rule. If an overpayment of tax is credited, interest shall be allowed from the date of overpayment to the due date (as determined under paragraph (d)(2) of this section of the amount against which such overpayment is credited.

Determination of due date—(i) General. The term due date, as used in this section, means the last day fixed by law or regulations for the payment of the tax (determined without regard to any extension of time), and not the date on which the appropriate TTB officer makes demand for the payment of the tax. Therefore, the due date of the tax is the date fixed for the payment of the tax;

Tax not due yet. If a taxpayer agrees to the crediting of an overpayment against tax and the schedule of allowance is signed prior to the date on which such tax would otherwise become due, then the due date of such tax shall be the date on which such schedule is signed;

Interest. In the case of a credit against interest that accrues for any period ending prior to January 1, 1983, the due date is the earlier of the date of assessment of such interest or December 31, 1982. In the case of a credit against interest that accrues from any period beginning on or after December 31, 1982, such interest is due as it economically accrues on a daily basis, rather than when it is assessed.

Additional amount, addition to the tax, or assessable penalty. In the case of a credit against an additional amount, addition to the tax, or assessable penalty, the due date is the earlier of the date of assessment or the date from which such amount would bear interest if not satisfied by payment or credit.