(a) Credit for foreign tax carryback or carryover (temporary). A taxpayer who chooses to claim a credit under section 901 for a taxable year is allowed a credit under that section not only for taxes otherwise allowable as a credit but also for taxes deemed paid or accrued in that year as a result of a carryback or carryover of an unused foreign tax under section 904(c). However, the taxes so deemed paid or accrued shall not be allowed as a deduction under section 164(a). Paragraphs (b) through (g) of § 1.904-2 and § 1.904-3, providing rules for the computation of carryovers and carrybacks, do not reflect a number of intervening statutory amendments, including the redesignation of section 904(d) as section 904(c) for taxable years beginning after 1975, amendments to sections 904(d) and (f) regarding the application of separate limitations in taxable years beginning after 1986, the limitation of the carryback period to one year for unused foreign taxes arising in taxable years beginning after October 22, 2004, and the extension of the carryover period to ten years for unused foreign taxes that may be carried to any taxable year ending after October 22, 2004. However, the principles of paragraphs (b) through (g) of § 1.904-2 and § 1.904-3 shall apply in determining carrybacks and carryovers of unused foreign taxes, modified so as to take into account the effect of statutory amendments. For transition rules relating to the carryover and carryback of unused foreign tax paid with respect to dividends from noncontrolled section 902 corporations, see paragraph (h) of this section. For special rules regarding these computations in case of taxes paid, accrued, or deemed paid with respect to foreign oil and gas extraction income or foreign oil related income, see section 907(f) and the regulations under that section.

(b) through (g) [Reserved]. For further guidance, see § 1.904-2(b) through (g).

(h) Transition rules for carryovers and carrybacks of pre-2003 and post-2002 unused foreign tax paid or accrued with respect to dividends from noncontrolled section 902 corporations (temporary)—(1) Carryover of unused foreign tax. Except as provided in §§ 1.904-7T(f)(9)(iv) and 1.904(f)-12T(g)(3), the rules of this paragraph (h)(1) apply to reallocate to the taxpayer's other separate categories any unused foreign taxes (as defined in § 1.904-2(b)(2)) that were paid or accrued or deemed paid under section 902 with respect to a dividend from a noncontrolled section 902 corporation paid in a taxable year of the noncontrolled section 902 corporation beginning before January 1, 2003, which taxes were subject to a separate limitation for dividends from that noncontrolled section 902 corporation. To the extent any such unused foreign taxes are carried forward to a taxable year of a domestic shareholder beginning on or after the first day of the noncontrolled section 902 corporation's first taxable year beginning after December 31, 2002, such taxes shall be allocated among the taxpayer's separate categories in the same proportions as the related dividend would have been assigned had such dividend been eligible for look-through treatment when paid. Accordingly, the taxes shall be allocated in the same percentages as the reconstructed earnings in the noncontrolled section 902 corporation's non-look-through pool and pre-1987 accumulated profits that were accumulated in taxable years beginning before January 1, 2003, out of which the dividend was paid, in accordance with the rules of § 1.904-7T(f), or, if the taxpayer elects the safe harbor of § 1.904-7T(f)(4)(ii), in the same percentages as the taxpayer properly characterizes the stock of the noncontrolled section 902 corporation for purposes of apportioning its interest expense in its first taxable year ending after the first day of the noncontrolled section 902 corporation's first taxable year beginning after December 31, 2002. See § 1.904-7T(f)(2) and (f)(4). In the case of unused foreign taxes allocable to dividends from a noncontrolled section 902 corporation with respect to which the taxpayer was no longer a domestic shareholder (as defined in § 1.902-1(a)) as of the first day of such taxable year, such taxes shall be allocated among the taxpayer's separate categories in the same percentages as the earnings in the noncontrolled section 902 corporation's non-look-through pool or pre-1987 accumulated profits would have been assigned had they been distributed in the last taxable year in which the taxpayer was a domestic shareholder in such corporation. The unused foreign taxes that are carried forward shall be treated as allocable to general limitation income to the extent that such taxes would otherwise have been allocable to passive income, either on a look-through basis or as a result of inadequate substantiation under the rules of § 1.904-7T(f)(4).

(2) Carryback of unused foreign tax. The rules of this paragraph (h)(2) apply to any unused foreign taxes that were paid or accrued or deemed paid under section 902 with respect to a dividend from a noncontrolled section 902 corporation paid in a taxable year of a noncontrolled section 902 corporation beginning after December 31, 2002, which dividends were eligible for look-through treatment. To the extent any such unused foreign taxes are carried back to a prior taxable year of a domestic shareholder, a credit for such taxes shall be allowed only to the extent of the excess limitation in the same separate category or categories to which the related look-through dividend was assigned and not in any separate category for dividends from noncontrolled section 902 corporations.

(i) Transition rules for carryovers and carrybacks of pre-2007 and post-2006 unused foreign tax—(1) Carryover of unused foreign tax—(i) General rule. For purposes of this paragraph (i), the terms post-2006 separate category and pre-2007 separate category have the meanings set forth in § 1.904-7T(g)(1)(ii) and (iii). The rules of this paragraph (i)(1) apply to reallocate to the taxpayer's post-2006 separate categories for general category income and passive category income any unused foreign taxes (as defined in § 1.904-2(b)(2)) that were paid or accrued or deemed paid under section 902 with respect to income in a pre-2007 separate category (other than a category described in § 1.904-4(m)). To the extent any such unused foreign taxes are carried forward to a taxable year beginning after December 31, 2006, such taxes shall be allocated to the taxpayer's post-2006 separate categories to which those taxes would have been allocated if the taxes were paid or accrued in a taxable year beginning after December 31, 2006. For example, any foreign taxes paid or accrued or deemed paid with respect to financial services income in a taxable year beginning before January 1, 2007, that are carried forward to a taxable year beginning after December 31, 2006, will be allocated to the general category because the financial services income to which those taxes relate would have been allocated to the general category if it had been earned in a taxable year beginning after December 31, 2006.

(ii) Safe harbor. In lieu of applying the rules of paragraph (i)(1)(i) of this section, a taxpayer may allocate all unused foreign taxes in the pre-2007 separate category for passive income to the post-2006 separate category for passive category income, and allocate all other unused foreign taxes described in paragraph (i)(1)(i) of this section to the post-2006 separate category for general category income.

(2) Carryback of unused foreign tax—(i) General rule. The rules of this paragraph (i)(2) apply to any unused foreign taxes that were paid or accrued or deemed paid under section 902 with respect to income in a post-2006 separate category (other than a category described in § 1.904-4(m)). To the extent any such unused foreign taxes are carried back to a taxable year beginning before January 1, 2007, a credit for such taxes shall be allowed only to the extent of the excess limitation in the pre-2007 separate category, or categories, to which the taxes would have been allocated if the taxes were paid or accrued in a taxable year beginning before January 1, 2007. For example, any foreign taxes paid or accrued or deemed paid with respect to income in the general category in a taxable year beginning after December 31, 2006, that are carried back to a taxable year beginning before January 1, 2007, will be allocated to the same separate categories to which the income would have been allocated if it had been earned in a taxable year beginning before January 1, 2007.

(ii) Safe harbor. In lieu of applying the rules of paragraph (i)(2)(i) of this section, a taxpayer may allocate all unused foreign taxes in the post-2006 separate category for passive category income to the pre-2007 separate category for passive income, and may allocate all other unused foreign taxes described in paragraph (i)(2)(i) of this section to the pre-2007 separate category for general limitation income.

(3) Effective/applicability date. This paragraph (i) applies to taxable years of United States taxpayers beginning after December 31, 2006 and ending on or after December 21, 2007.

(4) Expiration date. The applicability of this paragraph (i) expires on December 20, 2010.