26 U.S.C. § 6411: Tentative carryback and refund adjustments

The amount of the net operating loss, net capital loss, or unused business credit; The amount of the tax previously determined for the prior taxable year affected by such carryback, the tax previously determined being ascertained in accordance with the method prescribed in section 1314(a); The amount of decrease in such tax, attributable to such carryback, such decrease being determined by applying the carryback in the manner provided by law to the items on the basis of which such tax was determined; The unpaid amount of such tax, not including any amount required to be shown under paragraph (5); The amount, with respect to the tax for the taxable year immediately preceding the taxable year from which the carryback is made, as to which an extension of time for payment under section 6164 is in effect; and Such other information for purposes of carrying out the provisions of this section as may be required by such regulations. Within a period of 90 days from the date on which an application for a tentative carryback adjustment is filed under subsection (a), or from the last day of the month in which falls the last date prescribed by law (including any extension of time granted the taxpayer) for filing the return for the taxable year of the net operating loss, net capital loss, or unused business credit from which such carryback results, whichever is the later, the Secretary shall make, to the extent he deems practicable in such period, a limited examination of the application, to discover omissions and errors of computation therein, and shall determine the amount of the decrease in the tax attributable to such carryback upon the basis of the application and the examination, except that the Secretary may disallow, without further action, any application which he finds contains errors of computation which he deems cannot be corrected by him within such 90-day period or material omissions. Such decrease shall be applied against any unpaid amount of the tax decreased (including any amount of such tax as to which an extension of time under section 6164 is in effect) and any remainder shall be credited against any unsatisfied amount of any tax for the taxable year immediately preceding the taxable year of the net operating loss, net capital loss, or unused business credit the time for payment of which tax is extended under section 6164. Any remainder shall, within such 90-day period, be either credited against any tax or installment thereof then due from the taxpayer, or refunded to the taxpayer. If the corporation seeking a tentative carryback adjustment under this section, made or was required to make a consolidated return, either for the taxable year within which the net operating loss, net capital loss, or unused business credit arises, or for the preceding taxable year affected by such loss or credit, the provisions of this section shall apply only to such extent and subject to such conditions, limitations, and exceptions as the Secretary may by regulations prescribe. be verified in the same manner as an application under subsection (a), be filed during the period beginning on the date of filing the return for such taxable year and ending on the date 12 months from the last day of such taxable year, and the amount of the tax for such taxable year computed without regard to the deduction described in section 1341(a)(2), the amount of the tax for all prior taxable years for which the decrease in tax provided in section 1341(a)(5)(B) was computed, the amount determined under section 1341(a)(5)(B), the amount of the overpayment determined under section 1341(b)(1); and such other information as the Secretary may require. review the application, determine the amount of the overpayment, and apply, credit, or refund such overpayment, The provisions of subsection (c) shall apply to an adjustment under this subsection to the same extent and manner as the Secretary may by regulations provide.