A corporation may, after the close of the taxable year and on or before the 15th day of the fourth month thereafter, and before the day on which it files a return for such taxable year, file an application for an adjustment of an overpayment by it of estimated income tax for such taxable year. An application under this subsection shall not constitute a claim for credit or refund.
Within a period of 45 days from the date on which an application for an adjustment is filed under subsection (a), the Secretary shall make, to the extent he deems practicable in such period, a limited examination of the application to discover omissions and errors therein, and shall determine the amount of the adjustment upon the basis of the application and the examination; except that the Secretary may disallow, without further action, any application which he finds contains material omissions or errors which he deems cannot be corrected within such 45 days.
For purposes of this title (other than section 6655), any adjustment under this section shall be treated as a reduction, in the estimated income tax paid, made on the day the credit is allowed or the refund is paid.
If the corporation seeking an adjustment under this section paid its estimated income tax on a consolidated basis or expects to make a consolidated return for the taxable year, this section shall apply only to such extent and subject to such conditions, limitations, and exceptions as the Secretary may by regulations prescribe.