Taxable years beginning on or before December 31, 1963—(1) In general. In the case of a short taxable year of 9 months or more beginning on or before December 31, 1963, where the requirements of section 6016(a) are met before the 1st day of the 9th month of the short taxable year, the declaration shall be filed on or before the 15th day of the 9th month of such short year. In the case of a short taxable year of more than 9 months, where the requirements of section 6016(a) are first met after the last day of the 8th month, but before the 1st day of the last month of the short taxable year, the declaration shall be filed on or before the 15th day of the last month of such short year. See § 1.6016-4, relating to the requirement of a declaration in the case of a short taxable year, and paragraph (a) of § 1.6154-2, relating to the time for payment of the estimated tax in case of a short taxable year.

Example. The application of the provisions of this paragraph may be illustrated by the following example:

A corporation which changes from a calendar year basis to a fiscal year basis beginning November 1, 1960, will have a short taxable year beginning January 1, 1960, and ending October 31, 1960. If the requirements of section 6016(a) are met before September 1, 1960 (the 1st day of the 9th month), the corporation is required to file its declaration on or before September 15, 1960 (the 15th day of the 9th month). However, if the requirements of section 6016(a) are first met after August 31, 1960 (the last day of the 8th month), but before October 1, 1960 (the 1st day of the last month of the short year), the corporation is required to file its declaration on or before October 15, 1960 (the 15th day of the last month of the short year).

Taxable years beginning after December 31, 1963—(1) In general. In the case of a short taxable year of 4 or more months which begins after December 31, 1963, the declaration shall be filed on or before the applicable date specified in paragraph (b) of § 1.6074-1, except that in the case of a short taxable year ending after November 30, 1964, the declaration shall be filed on or before the 15th day of the last month of the short taxable year if the requirements of section 6016(a) are first met before the first day of such last month and the date specified in such paragraph (b) as applicable is not within the short taxable year. See § 1.6016-4, relating to the requirement of a declaration in the case of a short taxable year, and paragraph (b) of § 1.6154-2, relating to the time for payment of the estimated tax in case of a short taxable year.

Examples. The application of the provisions of this paragraph may be illustrated by the following examples:

A corporation filing on a calendar year basis which changes to a fiscal year beginning September 1, 1965, will have a short taxable year beginning January 1, 1965, and ending August 31, 1965. If the requirements of section 6016(a) are met before April 1, 1965 (the 1st day of the 4th month), the declaration of estimated tax must be filed on or before April 15, 1965 (the 15th day of the 4th month).

If, in the first example, the corporation first meets the requirements of section 6016(a) during July 1965, then the requirements of section 6016(a) were met before the first day of the last month of the short taxable year, and a declaration of estimated tax is required to be filed on or before August 15, 1965, for the short taxable year. However, if the corporation does not meet the requirements of section 6016(a) until August 1, 1965, then the requirements of section 6016(a) were not met before the first day of the last month of the short taxable year, and no declaration of estimated tax is required to be filed for the short taxable year.

Amendment of declaration—(1) Taxable years beginning on or before December 31, 1963. Where a declaration of estimated tax for a short taxable year of more than 9 months beginning on or before December 31, 1963, is filed before the 15th day of the last month of the short taxable year, an amended declaration may be filed any time on or before such 15th day.

Taxable years beginning after December 31, 1963. Where a declaration of estimated tax for a short taxable year beginning after December 31, 1963, has been filed, an amended declaration may be filed during any interval between installment dates. However, no amended declaration for a short taxable year may be filed until after the installment date on or before which the original declaration was filed and only one amended declaration may be filed during each interval between installment dates. For purposes of this subparagraph the term “installment date” includes the 15th day of the last month of a short taxable year if such 15th day does not fall on a prescribed installment date.