after the date of enactment of this title, and except that such period shall not, with the application of this amendment, expire prior to the date which is 3 years after the date of enactment of this title.) Where a complaint is instituted before a commissioner of the United States within the period above limited, the time shall be extended until the date which is 9 months after the date of the making of the complaint before the commissioner of the United States. For the purpose of determining the periods of limitation on criminal prosecutions, the rules of section 6513 shall be applicable.

SEC. 6532. PERIODS OF LIMITATION ON SUITS. (a) SUITS BY TAXPAYERS FOR REFUND.

(1) GENERAL RULE.-No suit or proceeding under section 7422 (a) for the recovery of any internal revenue tax, penalty, or other sum, shall be begun before the expiration of 6 months from the date of filing the claim required under such section unless the Secretary or his delegate renders a decision thereon within that time, nor after the expiration of 2 years from the date of mailing by certified mail or registered mail by the Secretary or his delegate to the taxpayer of a notice of the disallowance of the part of the claim to which the suit or proceeding relates.

(2) EXTENSION OF TIME.-The 2-year period prescribed in paragraph (1) shall be extended for such period as may be agreed upon in writing between the taxpayer and the Secretary or his delegate.

(3) WAIVER OF NOTICE OF DISALLOWANCE.-If any person files a written waiver of the requirement that he be mailed a notice of disallowance, the 2-year period prescribed in paragraph (1) shall begin on the date such waiver is filed.

(4) RECONSIDERATION AFTER MAILING OF NOTICE.-Any consideration, reconsideration, or action by the Secretary or his delegate with respect to such claim following the mailing of a notice by certified mail or registered mail of disallowance shall not operate to extend the period within which suit may be begun.

(b) SUITS BY UNITED STATES FOR RECOVERY OF ERRONEOUS REFUNDS.-Recovery of an erroneous refund by suit under section 7405 shall be allowed only if such suit is begun within 2 years after the making of such refund, except that such suit may be brought at any time within 5 years from the making of the refund if it appears that any part of the refund was induced by fraud or misrepresentation of a material fact.

SEC. 6533. CROSS REFERENCES.

(1) For period of limitation in respect of civil actions for fines, penalties, and forfeitures, see section 2462 of Title 28 of the United States Code. (2) For extensions of time by reason of armed service in a combat zone, see section 7508.

(3) For suspension of running of statute until 3 years after termination of hostilities, see section 3287 of Title 18.

CHAPTER 67-INTEREST

SUBCHAPTER A. Interest on underpayments.
SUBCHAPTER B. Interest on overpayments.

Subchapter A-Interest on Underpayments

Sec. 6601. Interest on underpayment, nonpayment, or extensions of time for payment, of tax.

Sec. 6602. Interest on erroneous refund recoverable by suit.

SEC. 6601. INTEREST ON UNDERPAYMENT, NONPAYMENT, OR EXTENSIONS OF TIME FOR PAYMENT, OF TAX.

(a) GENERAL RULE.-If any amount of tax imposed by this title (whether required to be shown on a return, or to be paid by stamp or by some other method) is not paid on or before the last date prescribed for payment, interest on such amount at the rate of 6 percent per annum shall be paid for the period from such last date to the date paid.

(b) EXTENSIONS OF TIME FOR PAYMENT OF ESTATE TAX.-If the time for payment of an amount of tax imposed by chapter 11 is extended as provided in section 6161 (a) (2) or 6166, or if the time for payment of an amount of such tax is postponed or extended as provided by section 6163, interest shall be paid at the rate of 4 percent, in lieu of 6 percent as provided in subsection (a).

(c) LAST DATE PRESCRIBED FOR PAYMENT.-For purposes of this section, the last date prescribed for payment of the tax shall be determined under chapter 62 with the application of the following rules:

(1) EXTENSIONS OF TIME DISREGARDED.-The last date prescribed for payment shall be determined without regard to any extension of time for payment.

(2) INSTALLMENT PAYMENTS.-In the case of an election under section 6152 (a) to pay the tax in installments

(A) The date prescribed for payment of each installment of the tax shown on the return shall be determined under section 6152 (b), and

(B) The last date prescribed for payment of the first installment shall be deemed the last date prescribed for payment of any portion of the tax not shown on the return.

(3) JEOPARDY.-The last date prescribed for payment shall be determined without regard to any notice and demand for payment issued, by reason of jeopardy (as provided in chapter 70), prior to the last date otherwise prescribed for such payment.

(4) LAST DATE FOR PAYMENT NOT OTHERWISE PRESCRIBED.-In the case of taxes payable by stamp and in all other cases in which the last date for payment is not otherwise prescribed, the last date for payment shall be deemed to be the date the liability for tax arises (and in no event shall be later than the date notice and demand for the tax is made by the Secretary or his delegate).

(d) SUSPENSION OF INTEREST IN CERTAIN INCOME, ESTATE, AND GIFT TAX CASES.-In the case of a deficiency as defined in section 6211 (relating to income, estate, and gift taxes), if a waiver of restrictions under section 6213 (d) on the assessment of such deficiency has been filed, and if notice and demand by the Secretary or his delegate for payment of such deficiency is not made within 30 days after the filing of such waiver, interest shall not be imposed on such deficiency for the period beginning immediately after such 30th day and ending with the date of notice and demand.

(e) INCOME TAX REDUCED BY CARRYBACK.-If the amount of any tax imposed by subtitle A is reduced by reason of a carry back of a net operating loss, such reduction in tax shall not affect the computation of interest under this section for the period ending with the last day of the taxable year in which the net operating loss arises.

(f) APPLICABLE RULES.-Except as otherwise provided in this title

(1) INTEREST TREATED AS TAX.-Interest prescribed under this section on any tax shall be paid upon notice and demand, and shall be assessed, collected, and paid in the same manner as taxes. Any reference in this title (except subchapter B of chapter 63, relating to deficiency procedures) to any tax imposed by this title shall be deemed also to refer to interest imposed by this section on such tax.

(2) NO INTEREST ON INTEREST.-No interest under this section shall be imposed on the interest provided by this section.

(3) INTEREST ON PENALTIES, ADDITIONAL AMOUNTS, OR ADDITIONS TO THE TAX.-Interest shall be imposed under subsection (a) in respect of any assessable penalty, additional amount, or addition to the tax only if such assessable penalty, additional amount, or addition to the tax is not paid within 10 days from the date of notice and demand therefor, and in such case interest shall be imposed only for the period from the date of the notice and demand to the date of payment.

(4) PAYMENTS MADE WITHIN 10 DAYS AFTER NOTICE AND DEMAND. If notice and demand is made for payment of any amount, and if such amount is paid within 10 days after the date of such notice and demand, interest under this section on the amount so paid shall not be imposed for the period after the date of such notice and demand.

(g) SATISFACTION BY CREDITS.-If any portion of a tax is satisfied by credit of an overpayment, then no interest shall be imposed under this section on the portion of the tax so satisfied for any period during which, if the credit had not been made, interest would have been allowable with respect to such overpayment.

(h) LIMITATION ON ASSESSMENT AND COLLECTION.-Interest prescribed under this section on any tax may be assessed and collected at any time during the period within which the tax to which such interest relates may be collected.

(i) EXCEPTION AS TO ESTIMATED TAX.-This section shall not apply to any failure to pay estimated tax required by section 6153 (or section 59 of the Internal Revenue Code of 1939) or section 6154.

(j) NO INTEREST ON CERTAIN ADJUSTMENTS.—

For provisions prohibiting interest on certain adjustments in tax, see section 6205 (a).

SEC. 6602. INTEREST ON ERRONEOUS REFUND RECOVERALBE BY SUIT.

Any portion of an internal revenue tax (or any interest, assessable penalty, additional amount, or addition to tax) which has been erroneously refunded, and which is recoverable by suit pursuant to section 7405, shall bear interest at the rate of 6 percent per annum from the date of the payment of the refund.