filing date
(4) Special rules for paragraphs (1), (2), and (3) (A) Filing date For purposes of this subsection, the term “filing date” means the last date prescribed for filing the return of tax imposed by subtitle A for the taxable year (determined without regard to extensions). (B) Coordination with subsection (e) (i) In general For purposes of subsection (e)— (I) any overpayment described in paragraph (1), (2), or (3) shall be treated as an overpayment for the loss year, (II) such subsection shall be applied with respect to such overpayment by treating the return for the loss year as not filed before claim for such overpayment is filed. (ii) Loss year For purposes of this subparagraph, the term “loss year” means— (I) in the case of a carryback of a net operating loss or net capital loss, the taxable year in which such loss arises, (II) in the case of a carryback of taxes paid or accrued to foreign countries or possessions of the United States, the taxable year in which such taxes were in fact paid or accrued (or, with respect to any portion of such carryback from a taxable year attributable to a net operating loss carryback or a capital loss carryback from a subsequent taxable year, such subsequent taxable year), and (III) in the case of a credit carryback (as defined in paragraph (3)(B)), the taxable year in which such credit carryback arises (or, with respect to any portion of a credit carryback from a taxable year attributable to a net operating loss carryback, a capital loss carryback, or other credit carryback from a subsequent taxable year, such subsequent taxable year). (C) Application of subparagraph (B) where section 6411(a) claim filed For purposes of subparagraph (B)(i)(II), if a taxpayer— (i) files a claim for refund of any overpayment described in paragraph (1), (2), or (3) with respect to the taxable year to which a loss or credit is carried back, and (ii) subsequently files an application under section 6411(a) with respect to such overpayment, then the claim for overpayment shall be treated as having been filed on the date the application under section 6411(a) was filed.