The Tax Court of the United States for a redetermination of the deficiency. No assessment of a deficiency in respect of the tax imposed by this chapter and no distraint or proceeding in court for its collection shall be made, begun, or prosecuted until such notice has been mailed to the taxpayer, nor until the expiration of such ninetyday period, nor, if a petition has been filed with the Tax Court, until the decision of the Tax Court has become final. Notwithstanding the provisions of section 3653 (a) the making of such assessment or the beginning of such proceeding or distraint during the time such prohibition is in force may be enjoined by a proceeding in the proper court. In the case of a joint return filed by husband and wife such notice of deficiency may be a single joint notice, except that if the Commissioner has been notified by either spouse that separate residences have been established, then, in lieu of the single joint notice, duplicate originals of the joint notice must be sent by registered mail to each spouse at his last known address. If the notice is addressed to a person outside the States of the Union and the District of Columbia, the period specified in this paragraph shall be one hundred and fifty days in lieu of ninety days.

(2) CROSS REFERENCES.

For exceptions to the restrictions imposed by this subsection, seeSubsection (d) of this section, relating to waivers by the taxpayer; Subsection (f) of this section, relating to notifications of mathematical errors appearing upon the face of the return;

Section 273, relating to jeopardy assessments;

Section 274, relating to bankruptcy and receiverships; and

Section 1145, relating to assessment or collection of the amount of the deficiency determined by the Tax Court pending court review.

(b) COLLECTION OF DEFICIENCY FOUND BY TAX COURT.-If the taxpayer files a petition with the Tax Court, the entire amount redetermined as the deficiency by the decision of the Tax Court which has become final shall be assessed and shall be paid upon notice and demand from the collector. No part of the amount determined as a deficiency by the Commissioner but disallowed as such by the decision of the Tax Court which has become final shall be assessed or be collected by distraint or by proceeding in court with or without assessment.

(c) FAILURE TO FILE PETITION.-If the taxpayer does not file a petition with the Tax Court within the time prescribed in subsection (a) of this section, the deficiency, notice of which has been mailed to the taxpayer, shall be assessed, and shall be paid upon notice and demand from the collector.

(d) WAIVER OF RESTRICTIONS.-The taxpayer shall at any time have the right, by a signed notice in writing filed with the Commissioner, to waive the restrictions provided in subsection (a) of this section on the assessment and collection of the whole or any part of the deficiency.

(e) INCREASE OF DEFICIENCY AFTER NOTICE MAILED.-The Tax Court shall have jurisdiction to redetermine the correct amount of the deficiency even if the amount so redetermined is greater than the amount of the deficiency, notice of which has been mailed to the taxpayer, and to determine whether any penalty, additional amount

or addition to the tax should be assessed-if claim therefor is asserted by the Commissioner at or before the hearing or a rehearing.

(f) FURTHER DEFICIENCY LETTERS RESTRICTED.-If the Commissioner has mailed to the taxpayer notice of a deficiency as provided in subsection (a) of this section, and the taxpayer files a petition with the Tax Court within the time prescribed in such subsection, the Commissioner shall have no right to determine any additional deficiency in respect of the same taxable year, except in the case of fraud, and except as provided in subsection (e) of this section, relating to assertion of greater deficiencies before the Tax Court, or in section 273 (c), relating to the making of jeopardy assessments. If the taxpayer is notified that, on account of a mathematical error appearing upon the face of the return, an amount of tax in excess of that shown upon the return is due, and that an assessment of the tax has been or will be made on the basis of what would have been the correct amount of tax but for the mathematical error, such notice shall not be considered (for the purposes of this subsection, or of subsection (a) of this section, prohibiting assessment and collection until notice of deficiency has been mailed, or of section 322 (c), prohibiting credits or refunds after petition to The Tax Court of the United States) as a notice of a deficiency, and the taxpayer shall have no right to file a petition with the Tax Court based on such notice, nor shall such assessment or collection be prohibited by the provisions of subsection (a) of this section.

(g) JURISDICTION OVER OTHER TAXABLE YEARS.-The Tax Court in redeterming a deficiency in respect of any taxable year shall consider such facts with relation to the taxes for other taxable years as may be necessary correctly to redetermine the amount of such deficiency, but in so doing shall have no jurisdiction to determine whether or not the tax for any other taxable year has been overpaid or underpaid.

(h) FINAL DECISIONS OF TAX COURT.-For the purposes of this chapter the date on which a decision of the Tax Court becomes final shall be determined according to the provisions of section 1140.

(i) PRORATING OF DEFICIENCY TO INSTALLMENTS.-If the taxpayer has elected to pay the tax in installments and a deficiency has been assessed, the deficiency shall be prorated to the four installments. Except as provided in section 273 (relating to jeopardy assessments), that part of the deficiency so prorated to any installment the date for payment of which has not arrived, shall be collected at the same time as and as part of such installment. That part of the deficiency so prorated to any installment the date for payment of which has arrived shall be paid upon notice and demand from the collector.

[See also section 293 (a).]

(j) EXTENSION OF TIME FOR PAYMENT OF DEFICIENCIES.-Where it is shown to the satisfaction of the Commissioner that the payment of a deficiency upon the date prescribed for the payment thereof will result in undue hardship to the taxpayer the Commissioner, under regulations prescribed by the Commissioner, with the approval of the Secretary, may grant an extension for the payment of such deficiency for a period not in excess of eighteen months, and, in exceptional

cases, for a further period not in excess of twelve months. If an extension is granted, the Commissioner may require the taxpayer to furnish a bond in such amount, not exceeding double the amount of the deficiency, and with such sureties, as the Commissioner deems necessary, conditioned upon the payment of the deficiency in accordance with the terms of the extension. No extension shall be granted if the deficiency is due to negligence, to intentional disregard of rules and regulations, or to fraud with intent to evade tax.

[See also section 3676.]

(k) ADDRESS FOR NOTICE OF DEFICIENCY.-In the absence of notice to the Commissioner, under section 312 (a), of the existence of a fiduciary relationship, notice of a deficiency in respect of a tax imposed by this chapter, if mailed to the taxpayer at his last known address, shall be sufficient for the purposes of this chapter even if such taxpayer is deceased, or is under a legal disability

SEC. 273. JEOPARDY ASSESSMENTS.

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(a) AUTHORITY FOR MAKING.-If the Commissioner believes that the assessment or collection of a deficiency will be jeopardized by delay, he shall immediately assess such deficiency (together with all interest, additional amounts, or additions to the tax provided for by law), and notice and demand shall be made by the collector for the payment thereof.

(b) DEFICIENCY LETTERS.-If the jeopardy assessment is made before any notice in respect of the tax to which the jeopardy assessment relates has been mailed under section 272 (a), then the Commissioner shall mail a notice under such subsection within sixty days after the making of the assessment.

(c) AMOUNT ASSESSABLE BEFORE DECISION OF TAX COURT.-The jeopardy assessment may be made in respect of a deficiency greater or less than that notice of which has been mailed to the taxpayer, despite the provisions of section 272 (f) prohibiting the determination of additional deficiencies, and whether or not the taxpayer has theretofore filed a petition with The Tax Court of the United States. The Commissioner may, at any time before the decision of the Tax Court is rendered, abate such assessment, or any unpaid portion thereof, to the extent that he believes the assessment to be excessive in amount. The Commissioner shall notify the Tax Court of the amount of such assessment, or abatement, if the petition is filed with the Tax Court before the making of the assessment or is subsequently filed, and the Tax Court shall have jurisdiction to redetermine the entire amount of the deficiency and of all amounts assessed at the same time in connection therewith.

(d) AMOUNT ASSESSABLE AFTER DECISION OF TAX COURT.-If the jeopardy assessment is made after the decision of the Tax Court is rendered, such assessment may be made only in respect of the deficiency determined by the Tax Court in its decision.

(e) EXPIRATION OF RIGHT TO ASSESS.-A jeopardy assessment may not be made after the decision of the Tax Court has become final or after the taxpayer has filed a petition for review of the decision of the Tax Court.

(f) BOND TO STAY COLLECTION.-When a jeopardy assessment has been made, the taxpayer, within 10 days after notice and demand from the collector for the payment of the amount of the assessment, may obtain a stay of collection of the whole or any part of the amount of the assessment by filing with the collector a bond in such amount, not exceeding double the amount as to which the stay is desired, and with such sureties, as the collector deems necessary, conditioned upon the payment of so much of the amount, the collection of which is stayed by the bond, as is not abated by a decision of the Tax Court which has become final, together with interest thereon as provided in section 297. If any portion of the jeopardy assessment is abated by the Commissioner before the decision of the Tax Court is rendered, the bond shall, at the request of the taxpayer, be proportionately reduced.

(g) SAME FURTHER CONDITIONS.-If the bond is given before the taxpayer has filed his petition with the Tax Court under section 272 (a), the bond shall contain a further condition that, if a petition is not filed within the period provided in such subsection, then the amount the collection of which is stayed by the bond will be paid on notice and demand at any time after the expiration of such period, together with interest thereon at the rate of 6 per centum per annum from the date of the jeopardy notice and demand to the date of notice and demand under this subsection.

(h) WAIVER OF STAY.-Upon the filing of the bond the collection of so much of the amount assessed as is covered by the bond shall be stayed. The taxpayer shall have the right to waive such stay at any time in respect of the whole or any part of the amount covered by the bond, and if as a result of such waiver any part of the amount covered by the bond is paid, then the bond shall, at the request of the taxpayer, be proportionately reduced. If the Tax Court determines that the amount assessed is greater than the amount which should have been assessed, then when the decision of the Tax Court is rendered the bond shall, at the request of the taxpayer, be proportionately reduced.

(i) COLLECTION OF UNPAID AMOUNTS.-When the petition has been filed with the Tax Court and when the amount which should have been assessed has been determined by a decision of the Tax Court which has become final, then any unpaid portion, the collection of which has been stayed by the bond, shall be collected as part of the tax upon notice and demand from the collector, and any remaining portion of the assessment shall be abated. If the amount already collected exceeds the amount determined as the amount which should have been assessed, such excess shall be credited or refunded to the taxpayer as provided in section 322, without the filing of claim therefor. If the amount determined as the amount which should have been assessed is greater than the amount actually assessed, then the difference shall be assessed and shall be collected as part of the tax upon notice and demand from the collector.

(i) CLAIMS IN ABATEMENT.-No claim in abatement shall be filed in respect of any assessment in respect of any tax imposed by this chapter.

SEC. 274. BANKRUPTCY AND RECEIVERSHIPS.

(a) IMMEDIATE ASSESSMENT.-Upon the adjudication of bank. ruptcy of any taxpayer in any bankruptcy proceeding or the appointment of a receiver for any taxpayer in any receivership proceeding before any court of the United States or of any State or Territory or of the District of Columbia, any deficiency (together with all interest, additional amounts, or additions to the tax provided for by law) determined by the Commissioner in respect of a tax imposed by this chapter upon such taxpayer shall, despite the restrictions imposed by section 272 (a) upon assessments be immediately assessed if such deficiency has not theretofore been assessed in accordance with law. In such cases the trustee in bankruptcy or receiver shall give notice in writing to the Commissioner of the adjudication of bankruptcy or the appointment of the receiver, and the running of the statute of limitations on the making of assessments shall be suspended for the period from the date of adjudication in bankruptcy or the appointment of the receiver to a date 30 days after the date upon which the notice from the trustee or receiver is received by the Commissioner; but the suspension under this sentence shall in no case be for a period in excess of two years. Claims for the deficiency and such interest, additional amounts and additions to the tax may be presented, for adjudication in accordance with law, to the court before which the bankruptcy or receivership proceeding is pending, despite the pendency of proceedings for the redetermination of the deficiency in pursuance of a petition to the Tax Court; but no petition for any such redetermination shall be filed with the Tax Court after the adjudication of bankruptcy or the appointment of the receiver.

(b) UNPAID CLAIMS.-Any portion of the claim allowed in such bankruptcy or receivership proceeding which is unpaid shall be paid by the taxpayer upon notice and demand from the collector after the termination of such proceeding, and may be collected by distraint or proceeding in court within 6 years after termination of such proceeding. Extensions of time for such payment may be had in the same manner and subject to the same provisions and limitations as are provided in section 272 (j) and section 296 in the case of a deficiency in a tax imposed by this chapter.

SEC. 275. PERIOD OF LIMITATION UPON ASSESSMENT AND COLLECTION.

Except as provided in section 276—

(a) GENERAL RULE.-The amount of income taxes imposed by this chapter shall be assessed within three years after the return was filed, and no proceeding in court without assessment for the collection of such taxes shall be begun after the expiration of such period.

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(b) REQUEST FOR PROMPT ASSESSMENT.-In the case of income received during the lifetime of a decedent, or by his estate during the period of administration, the tax shall be assessed, and any proceeding in court without assessment for the collection of such tax shall be begun, within eighteen months after written request therefor (filed after the return is made) by the executor, administrator, or other fiduciary representing the estate of such decedent, but not after the expiration of three years after the return was filed.

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