PUBLIC LAWS--CH. 258-JULY 16, 1947 Assessment within three years. Request for assess- ment. Applicability to cor- poration. Omission from gross income. Return filed prior to last day. Suspension of pe- riods of limitation. persons liable to pay the same to the District and shall be entitled to the same priority as other District taxes, and the taxes levied under this article and the interest and penalties thereon shall be collected by the Collector in the manner provided by law for the collection of taxes due the District on personal property in force at the time of such collection. SEC. 10. PERIOD OF LIMITATION UPON ASSESSMENT AND COLLECTION.- (a) GENERAL RTLE. - Except as provided in subsection (b) of this section- (1) the amount of income taxes imposed by this article shall be assessed within three years after the return is filed, and no proceeding in court without assessment for the collection of such taxes shall be begun after the expiration of such period; (2) in the case of income received during the lifetime of a decedent, or by his estate during the period of administration, or by a corporation, the tax shall be assessed, and any proceeding in court without assessment for the collection of such tax shall be begun within twelve months after written request therefor (filed after the return is made) by the executor, administrator, or other fiduciary representing the estate of such decedent, or by the corpo- ration, but not after the expiration of three years after the return is filed. This subsection shall not apply in the case of a corpora- tion unless- (A) such written request notifies the Assessor that the corporation contemplates dissolution at or before the expira- tion of such twelve-month period; and (B) the dissolution is in good faith begun before the expiration of such twelve-month period; and (C) the dissolution is completed; (3) if the taxpayer omits from gross income an amount prop- erly includible therein which is in excess of 25 per centum of the amount of gross income stated in the return, the tax may be assessed, or a proceeding in court for the collection of such tax may be begun without assessment, at any time within five years after the return was filed; (4) for the purposes of subsections (a) (1), (a) (2), and (a) (3), a return filed before the last day prescribed by law for the filing thereof shall be considered as filed on such last day: Pro- vided, however, That the periods of limitation upon the assessment and collection of taxes provided in this section in cases where the taxpayer has appealed to the Board of Tax Appeals as provided in this article shall be suspended until such cases have been finally disposed of in the Board of Tax Appeals by final decision, dis- missal, or otherwise. (b) FALSE RETURN.--In the case of a false or fraudulent return with intent to evade tax or of a failure to file a return, the tax may be assessed, or a proceeding in court for the collection of such tax may be begun without assessment, at any time. (c) WAIVE.- Where before the expiration of the time prescribed in subsection (a) for the assessment of the tax, both the Assessor and the taxpayer have consented in writing to its assessment after such time, the tax may be assessed at any time prior to the expira- tion of the period agreed upon. The period so agreed upon may be extended by subsequent agreements in writing made before the expiration of the period previously agreed upon. (d) COLLECTION AfIER AssESSMENT. - W here the assessment of any income tax imposed by this article has been made within the period of limitation properly applicable thereto, such tax may be collected by distraint or by a proceeding in court, but only if begun [61 STAT.