26 C.F.R. § 1.901(m)-3

Current through October 31, 2024
Section 1.901(m)-3 - Disqualified tax amount and aggregate basis difference carryover
(a)In general. If a section 901(m) payor has an aggregate basis difference, with respect to a foreign income tax and a foreign payor, for a U.S. taxable year, the section 901(m) payor must determine the portion of a foreign income tax amount that is disqualified under section 901(m) (disqualified tax amount). Paragraph (b) of this section provides rules for determining the disqualified tax amount. Paragraph (c) of this section provides rules for determining what portion, if any, of aggregate basis difference will be carried forward to the next U.S. taxable year (aggregate basis difference carryover). Paragraph (d) of this section provides applicability dates.
(b)Disqualified tax amount -
(1)In general. A section 901(m) payor's disqualified tax amount is not taken into account in determining the credit allowed under section 901(a). If the section 901(m) payor is an applicable foreign corporation, the disqualified tax amount is not taken into account for purposes of section 902 (for tax years of foreign corporations beginning before January 1, 2018) or 960. Sections 78 and 275 do not apply to the disqualified tax amount. The disqualified tax amount is allowed as a deduction to the extent otherwise deductible. See sections 164, 212, and 964 and the regulations under those sections.
(2)Determination of disqualified tax amount -
(i)In general. Except as provided in paragraph (b)(2)(iv) of this section, the disqualified tax amount is equal to the lesser of the foreign income tax amount that is paid or accrued by, or considered paid or accrued by, the section 901(m) payor for the U.S. taxable year or the tentative disqualified tax amount. All calculations are determined with respect to each separate category.
(ii)Tentative disqualified tax amount. The tentative disqualified tax amount is equal to the amount determined under paragraph (b)(2)(ii)(A) of this section reduced (but not below zero) by the amount described in paragraph (b)(2)(ii)(B) of this section.
(A) The product of-
(1) The sum of the foreign income tax amount and the FCCTs that are paid or accrued by, or considered paid or accrued by, the section 901(m) payor, and
(2) A fraction, the numerator of which is the aggregate basis difference, but not in excess of the allocable foreign income, and the denominator of which is the allocable foreign income.
(B) The amount of the FCCT that is a disqualified tax amount of the section 901(m) payor with respect to another foreign income tax.
(iii)Allocable foreign income -
(A)No allocation required. Except as provided in paragraph (b)(2)(iii)(D) of this section, if the entire foreign income tax amount is paid or accrued by, or considered paid or accrued by, a single section 901(m) payor, then the allocable foreign income is equal to the entire foreign income, determined with respect to each separate category.
(B)Allocation required. Except as provided in paragraph (b)(2)(iii)(D) of this section, if the foreign income tax amount is allocated to, and considered paid or accrued by, more than one person, a section 901(m) payor's allocable foreign income is equal to the portion of the foreign income that relates to the foreign income tax amount allocated to that section 901(m) payor, determined with respect to each separate category.
(C)Rules for allocations. This paragraph (b)(2)(iii)(C) provides allocation rules that apply to determine allocable foreign income in certain cases.
(1) If the foreign payor is involved in a mid-year transaction and the foreign income tax amount is allocated under § 1.336-2(g)(3)(ii) , § 1.338-9(d) , or § 1.901-2(f)(4) , then, to the extent any portion of the foreign income tax amount is allocated to, and considered paid or accrued by, a section 901(m) payor, the allocable foreign income of the section 901(m) payor is determined in accordance with the principles of § 1.1502-76(b) . To the extent the foreign income tax amount is allocated to an entity that is a partnership for U.S. income tax purposes, a portion of the foreign income is first allocated to the partnership in accordance with the principles of § 1.1502-76(b) , which is then allocated under the rules of paragraph (b)(2)(iii)(C)(2) of this section to determine the allocable foreign income of a section 901(m) payor that owns an interest in the partnership directly or indirectly through one or more other partnerships for U.S. income tax purposes.
(2) If the foreign income tax amount is considered paid or accrued by a section 901(m) payor for a U.S. taxable year under § 1.702-1(a)(6) , the determination of the allocable foreign income must be consistent with the allocation of the foreign income tax amount that relates to the foreign income. See § 1.704-1(b)(4) (viii).
(3) If the foreign income tax amount that is allocated to, and considered paid or accrued by, a section 901(m) payor for a U.S. taxable year is determined under § 1.901-2(f)(3)(i) , the allocable foreign income is determined in accordance with § 1.901-2(f)(3)(iii) .
(D)Failure to substantiate allocable foreign income. If, pursuant to section 901(m)(3)(A), a section 901(m) payor fails to substantiate its allocable foreign income to the satisfaction of the Secretary, then allocable foreign income will equal the amount determined by dividing the sum of the foreign income tax amount and the FCCTs that are paid or accrued by, or considered paid or accrued by, the section 901(m) payor, by the highest marginal tax rate applicable to income of the foreign payor under foreign tax law.
(iv)Special rule. A section 901(m) payor's disqualified tax amount is zero for a U.S. taxable year if:
(A) The section 901(m) payor's aggregate basis difference for the U.S. taxable year is a negative amount;
(B) Foreign income is less than or equal to zero for the foreign taxable year of the foreign payor; or
(C) The foreign income tax amount that is paid or accrued by, or considered paid or accrued by, the section 901(m) payor for the U.S. taxable year is zero.
(3)Examples. The following examples illustrate the rules of paragraph (b)(2) of this section. For purposes of all the examples, unless otherwise specified: USP is a domestic corporation. CFC1, CFC2, DE1, and DE2 are organized in Country F and are treated as corporations for Country F tax purposes. CFC1 and CFC2 are applicable foreign corporations. DE1 and DE2 are disregarded entities. USP, CFC1, and CFC2 each have a calendar year for both U.S. and Country F income tax purposes, and DE1 and DE2 each have a calendar year for Country F tax purposes. Country F and Country G each impose a single tax that is a foreign income tax. CFC1, CFC2, DE1, and DE2 each have a functional currency of the u with respect to all activities. At all relevant times, 1u equals $1. All amounts are stated in millions. The examples assume that the applicable cost recovery method for property results in basis being recovered ratably over the life of the property beginning on the first day of the U.S. taxable year in which the property is acquired or placed into service; there is a single separate category with respect to a foreign income and foreign income tax amount; and a section 901(m) payor properly substantiates its allocable foreign income to the satisfaction of the Secretary.
(i)Example 1: Determining aggregate basis difference; multiple foreign payors -
(A)Facts. CFC1 wholly owns CFC2 and DE1. DE1 wholly owns DE2. Assume that the tax laws of Country F do not allow combined income reporting or the filing of consolidated income tax returns. Accordingly, CFC1, CFC2, DE1, and DE2 file separate tax returns for Country F tax purposes. USP acquires all of the stock of CFC1 in a qualified stock purchase (as defined in section 338(d)(3)) to which section 338(a) applies for both CFC1 and CFC2.
(B)Result.
(1) The acquisition of CFC1 gives rise to four separate CAAs under § 1.901(m)-2(b) . The acquisition of the stock of CFC1 and the deemed purchase of the stock of CFC2 under section 338(h)(3)(B) are each a section 338 CAA under § 1.901(m)-2(b)(1) . Furthermore, because the deemed purchase of the assets of DE1 and DE2 for U.S. income tax purposes is disregarded for Country F tax purposes, each acquisition is a CAA under § 1.901(m)-2(b)(2) . Because these four CAAs occur pursuant to a plan, under § 1.901(m)-1(a)(3) they are part of an aggregated CAA transaction. Under § 1.901(m)-1(a)(37) , CFC1 is the RFA owner (U.S.) with respect to its assets and those of DE1 and DE2. CFC2 is the RFA owner (U.S.) with respect to its assets. Under § 1.901(m)-1(a)(28) , CFC1, CFC2, DE1, and DE2 are each a foreign payor for Country F tax purposes. Under § 1.901(m)-1(a)(41) , CFC1 is the section 901(m) payor with respect to foreign income tax amounts for which CFC1, DE1, and DE2 are the foreign payors (see § 1.901-2(f)(1) and (f)(4)(ii) ). CFC2 is the section 901(m) payor with respect to foreign income tax amounts for which CFC2 is the foreign payor (see § 1.901-2(f)(1) ).
(2) In determining aggregate basis difference under § 1.901(m)-1(a)(1) for a U.S. taxable year of CFC1, CFC1 has three computations with respect to Country F tax, because there are three foreign payors for Country F tax purposes whose foreign income tax amount, if any, is considered paid or accrued by CFC1 as the section 901(m) payor. Furthermore, for each U.S. taxable year, CFC1 will compute a separate disqualified tax amount and aggregate basis difference carryover (if any) under paragraph (b)(2) of this section, with respect to each foreign payor.
(3) In determining aggregate basis difference for a U.S. taxable year of CFC2 under § 1.901(m)-1(a)(1) , CFC2 has a single computation with respect to Country F tax, because there is a single foreign payor (CFC2) for Country F tax purposes whose foreign income tax amount, if any, is considered paid or accrued by CFC2 as the section 901(m) payor. Furthermore, for each U.S. taxable year, CFC2 will compute a disqualified tax amount and aggregate basis difference carryover (if any) under paragraph (b)(2) of this section.
(C)Alternative facts. Assume the same facts as in paragraph (b)(3)(i)(A) of this section (paragraph (A) of this Example 1), except that foreign income for Country F tax purposes is based on combined income (within the meaning of § 1.901-2(f)(3)(ii) ) of CFC1, CFC2, DE1, and DE2. For purposes of determining an aggregate basis difference for a U.S. taxable year of CFC1 under § 1.901(m)-1(a)(1) , CFC1, DE1, and DE2 are treated as a single foreign payor because all of the items of income, deduction, gain, or loss with respect to CFC1, DE1, and DE2 are included in the earnings and profits of CFC1 for U.S. income tax purposes. For each U.S. taxable year, CFC1 will therefore compute a single aggregate basis difference, disqualified tax amount, and aggregate basis difference carryover. The result for CFC2 under the alternative facts is the same as in paragraph (b)(3)(i)(B)(3) (paragraph (B)(3) of this Example 1).
(ii) Example 2: Computation of disqualified tax amount -
(A)Facts. On December 31 of Year 0, USP acquires all of the stock of CFC1 in a qualified stock purchase (as defined in section 338(d)(3)) to which section 338(a) applies (Acquisition). CFC1 owns four assets (Asset A, Asset B, Asset C, and Asset D, and collectively, Assets) and conducts activities in Country F and in a Country G branch. The activities conducted by CFC1 in Country G are not subject to tax in Country F. The tax rate is 25% in Country F and 30% in Country G. For Country F tax purposes, CFC1's foreign income and foreign income tax amount for each foreign taxable year 1 through 15 is 100u and $25 (25u translated at the exchange rate of $1 = 1u), respectively. For Country G tax purposes, CFC1's foreign income and foreign income tax amount for each foreign taxable year 1 through 5 is 400u and $120 (120u translated at the exchange rate of $1 = 1u), respectively. No dispositions occur for any of the Assets during the applicable cost recovery period. Additional facts relevant to each of the Assets are summarized below.

Assets Relevant foreign
income tax
Basis
difference
Applicable
cost recovery
period
(years)
Cost recovery amount
Asset ACountry F tax150u1510u (150u/15).
Asset BCountry F tax50u510u (50u/5).
Asset CCountry G tax300u560u (300u/5).
Asset DCountry G tax(100u)5negative 20u (negative 100/5).

(B)Result.
(1) Under § 1.901(m)-2(b)(1) , the acquisition of the stock of CFC1 is a section 338 CAA. Under § 1.901(m)-2(c)(1) , Assets A and B are RFAs with respect to Country F tax, because they are relevant in determining foreign income of CFC1 for Country F tax purposes and were owned by CFC1 when the Acquisition occurred. Assets C and D are RFAs with respect to Country G tax, because they are relevant in determining foreign income of CFC1 for Country G tax purposes and were owned by CFC1 when the Acquisition occurred. Under § 1.901(m)-1(a)(37) , CFC1 is the RFA owner (U.S.) with respect to all of the RFAs. Under § 1.901(m)-1(a)(41) and (28) , CFC1 is the section 901(m) payor and the foreign payor for Country F and Country G tax purposes.
(2) In determining aggregate basis difference for a U.S. taxable year of CFC1, CFC1 has two computations, one with respect to Country F tax and one with respect to Country G tax. Under § 1.901(m)-1(a)(1) , the aggregate basis difference for a U.S. taxable year with respect to Country F tax is equal to the sum of the allocated basis differences and allocated basis difference adjustments with respect to Assets A and B for the U.S. taxable year. Under § 1.901(m)-1(a)(5) , allocated basis differences are the sum of cost recovery amounts and disposition amounts. Because there are no dispositions, the only allocated basis differences taken into account in determining an aggregate basis difference are cost recovery amounts. Under § 1.901(m)-5(b) , any cost recovery amounts are attributed to CFC1, because CFC1 is the section 901(m) payor and RFA owner (U.S.) with respect to all of the Assets. For each U.S. taxable year, CFC1 will compute a separate disqualified tax amount and aggregate basis difference carryover (if any) with respect to Country F tax and Country G tax under paragraph (b)(2) of this section. For purposes of both disqualified tax amount computations, because CFC1 is the section 901(m) payor and foreign payor, the foreign income tax amount paid or accrued by CFC1 with respect to Country F tax and Country G tax, respectively, will be the entire foreign income tax amount and CFC1's allocable foreign income will be the entire foreign income.
(3) With respect to Country F tax, in U.S. taxable years 1 through 5, CFC1 has an aggregate basis difference of 20u each year (10u cost recovery amount with respect to Asset A plus 10u cost recovery amount with respect to Asset B). For U.S. taxable years 1 through 5, under paragraph (b)(2) of this section, the disqualified tax amount each year is $5, the lesser of two amounts: the tentative disqualified tax amount, in this case, $5 ($25 foreign income tax amount * (20u aggregate basis difference/100u allocable foreign income)), or the foreign income tax amount paid or accrued by CFC1, in this case, $25. After U.S. taxable year 5, Asset B has no unallocated basis difference with respect to Country F tax. Accordingly, in U.S. taxable years 6 through 15, CFC1 has an aggregate basis difference of 10u each year. Accordingly, for U.S. taxable years 6 through 15, the disqualified tax amount each year is $2.50, the lesser of two amounts: the tentative disqualified tax amount, in this case, $2.50 ($25 foreign income tax amount * (10u aggregate basis difference/100u allocable foreign income)), or the foreign income tax amount paid or accrued by CFC1, in this case, $25. After U.S. taxable year 15, Asset A has no unallocated basis difference with respect to Country F tax and, therefore, CFC1 has no disqualified tax amount with respect to Country F Tax.
(4) With respect to Country G tax, in U.S. taxable years 1 through 5, CFC1 has an aggregate basis difference of 40u each year (60u cost recovery amount with respect to Asset C + (20u) cost recovery amount with respect to Asset D). For U.S. taxable years 1 through 5, under paragraph (b)(2) of this section, the disqualified tax amount each year is $12, the lesser of two amounts: the tentative disqualified tax amount, in this case, $12 ($120 foreign income tax amount * (40u aggregate basis difference/400u allocable foreign income)), or the foreign income tax amount paid or accrued by CFC1, in this case, $120. After U.S. taxable year 5, Asset C and Asset D have no unallocated basis difference with respect to Country G tax. Accordingly, in U.S. taxable years 6 through 15, CFC1 has no disqualified tax amount with respect to Country G Tax.
(iii)Example 3: FCCT -
(A)Facts. In U.S. taxable year 1, USP acquires all of the interests in DE1 in a transaction (Transaction) that is treated as a stock acquisition for Country F tax purposes. Immediately after the Transaction, DE1 owns assets (Pre-Transaction Assets), all of which are used in a Country G branch and give rise to income that is taken into account for Country F tax and Country G tax purposes. After the Transaction, DE1 acquires additional assets (Post-Transaction Assets), which are not used by the Country G branch. Both Country F and Country G have a tax rate of 30%. Country F imposes worldwide tax on its residents and provides a foreign tax credit for taxes paid to other jurisdictions. In foreign taxable year 3, 100u of income is attributable to DE1's Post-Transaction Assets and 100u of income is attributable to DE1's Pre-Transaction Assets. For Country G tax purposes, the foreign income is 100u and foreign income tax amount is 30u (30% * 100u). For Country F tax purposes, the foreign income is 200u and the pre-foreign tax credit tax is 60u (30% * 200u). The 60u of Country F pre-foreign tax credit tax is reduced by the 30u foreign income tax amount imposed for Country G tax purposes. Thus, the foreign income tax amount for Country F tax purposes is $30 (30u translated into dollars at the exchange rate of $1 = 1u). Assume that for U.S. taxable year 3 USP has 100u aggregate basis difference with respect to Country F tax and 100u aggregate basis difference with respect to Country G tax. USP does not dispose of DE1 or any assets of DE1 in U.S. taxable year 3.
(B)Result.
(1) Under § 1.901(m)-2(b)(2) , the Transaction is a CAA. Under § 1.901(m)-2(c)(1) , the Pre-Transaction Assets are RFAs with respect to both Country F tax and Country G tax, because they are relevant in determining the foreign income of DE1 for Country F tax and Country G tax purposes and were owned by DE1 when the Transaction occurred. Under § 1.901(m)-1(a)(37) , USP is the RFA owner (U.S.) with respect to the RFAs. Under § 1.901(m)-1(a)(28) , DE1 is a foreign payor for Country F tax and Country G tax purposes. Under § 1.901(m)-1(a)(41) , USP is the section 901(m) payor with respect to foreign income tax amounts for which DE1 is the foreign payor (see § 1.901-2(f)(4)(ii) ). Because the Country G foreign income tax amount is claimed as a credit for purposes of determining the Country F foreign income tax amount, the Country G foreign income tax amount is an FCCT under § 1.901(m)-1(a)(22) .
(2) Under § 1.901(m)-1(a)(1) , for each U.S. taxable year, USP will separately compute the aggregate basis difference with respect to Country F tax and with respect to Country G tax and will use those amounts to separately compute a disqualified tax amount and aggregate basis difference carryover (if any) with respect to each foreign income tax. Because DE1 is a disregarded entity owned by USP during the entire U.S. taxable year 3, the foreign income tax amount paid or accrued by DE1 is not subject to allocation. Accordingly, for purposes of each of the disqualified tax amount computations, the foreign income tax amount paid or accrued by USP with respect to Country F tax and Country G tax, respectively, is the entire foreign income tax amount paid or accrued by DE1, and, under paragraph (b)(2)(iii)(A) of this section, USP's allocable foreign income will be equal to DE1's entire foreign income.
(3) As stated in paragraph (b)(3)(iii)(A) of this section (paragraph (A) of this Example 3), for U.S. taxable year 3 USP has 100u aggregate basis difference with respect to Country F tax and 100u aggregate basis difference with respect to Country G tax. With respect to Country G tax, in U.S. taxable year 3, under paragraph (b)(2) of this section, the disqualified tax amount is $30, the lesser of the two amounts: the tentative disqualified tax amount, in this case, $30 ($30 foreign income tax amount * (100u aggregate basis difference/100u allocable foreign income)), or the foreign income tax amount considered paid or accrued by USP, in this case, $30.
(4) With respect to Country F tax, in U.S. taxable year 3, under paragraph (b)(2) of this section, the disqualified tax amount is $0, the lesser of two amounts: the tentative disqualified tax amount, in this case $0 (($30 foreign income tax amount + $30 Country G FCCT) * (100u aggregate basis difference/200u foreign income) = $30 reduced by $30 Country G FCCT that is a disqualified tax amount of USP), or the foreign income tax amount considered paid or accrued by USP, in this case, $30.
(c)Aggregate basis difference carryover -
(1)In general. If a section 901(m) payor has an aggregate basis difference carryover for a U.S. taxable year, as determined under this paragraph (c), the aggregate basis difference carryover is taken into account in computing the section 901(m) payor's aggregate basis difference for the next U.S. taxable year. For successor rules that apply to an aggregate basis difference carryover, see § 1.901(m)-6(c) .
(2)Amount of aggregate basis difference carryover.
(i) If a section 901(m) payor's disqualified tax amount is zero, all of the section 901(m) payor's aggregate basis difference (positive or negative) for the U.S. taxable year gives rise to an aggregate basis difference carryover to the next U.S. taxable year.
(ii) If a section 901(m) payor's disqualified tax amount is not zero, then aggregate basis difference carryover can arise in either or both of the following two situations:
(A) If a section 901(m) payor's aggregate basis difference for the U.S. taxable year exceeds its allocable foreign income, the excess gives rise to an aggregate basis difference carryover.
(B) If the tentative disqualified tax amount exceeds the disqualified tax amount, the excess tentative disqualified tax amount is converted into aggregate basis difference carryover by multiplying such excess by a fraction, the numerator of which is the allocable foreign income, and the denominator of which is the sum of the foreign income tax amount and the FCCTs that are paid or accrued by, or considered paid or accrued by, the section 901(m) payor.
(3)Example. The following example illustrates the rules of paragraph (c) of this section.
(i)Facts.
(A) On July 1 of Year 1, CFC1 acquires all of the interests of DE1 in a transaction (Transaction) that is treated as a stock acquisition for Country F tax purposes. CFC1 and DE1 are organized in Country F and are treated as corporations for Country F tax purposes. CFC1 is an applicable foreign corporation, and DE1 is a disregarded entity. CFC1 has a calendar year for U.S. income tax purposes, and DE1 has a June 30 year-end for Country F tax purposes. Country F imposes a single tax that is a foreign income tax. CFC1 and DE1 each have a functional currency of the u with respect to all activities. Immediately after the Transaction, DE1 owns one asset, Asset A, that gives rise to income that is taken into account for Country F tax purposes. For the first U.S. taxable year (U.S. taxable year 1) there is a cost recovery amount with respect to Asset A of 9u, and for each subsequent U.S. taxable year until the U.S. basis is fully recovered, there is a cost recovery amount with respect to Asset A of 18u. There is no disposition of Asset A.
(ii)Result.
(A) Under § 1.901(m)-2(b)(2) , the Transaction is a CAA. Under § 1.901(m)-2(c)(1) , Asset A is an RFA with respect to Country F tax because it is relevant in determining the foreign income of DE1 for Country F tax purposes and was owned by DE1 when the Transaction occurred. Under § 1.901(m)-1(a)(37) , CFC1 is the RFA owner (U.S.) with respect to Asset A. Under § 1.901(m)-1(a)(28) , DE1 is a foreign payor for Country F tax purposes. Under § 1.901(m)-1(a)(41) , CFC1 is the section 901(m) payor with respect to foreign income tax amounts for which DE1 is the foreign payor (see § 1.901-2(f)(4)(ii) ).
(B) Under § 1.901(m)-1(a)(1) , in determining the aggregate basis difference for U.S. taxable year 1, CFC1 has one computation with respect to Country F tax. Under § 1.901(m)-1(a)(1) , aggregate basis difference with respect to Country F tax is equal to the sum of allocated basis differences and allocated basis difference adjustments with respect to all RFAs, which, in this case, is only Asset A. Under § 1.901(m)-1(a)(5) , allocated basis differences are the sum of cost recovery amounts and disposition amounts. Because there is no disposition of Asset A, the only allocated basis difference taken into account in determining an aggregate basis difference are cost recovery amounts with respect to Asset A. Under § 1.901(m)-5(b) , any cost recovery amounts are assigned to a U.S taxable year of CFC1, because CFC1 is the section 901(m) payor and RFA owner (U.S.) with respect to Asset A. Under paragraph (b)(2) of this section, for each U.S. taxable year, CFC1 will compute a disqualified tax amount and aggregate basis difference carryover with respect to the aggregate basis difference. Because DE1 is a disregarded entity owned by CFC1, the foreign income tax amount paid or accrued by DE1 is not subject to allocation. Accordingly, for purposes of the disqualified tax amount computation, the foreign income tax amount paid or accrued by CFC1 with respect to Country F tax is the entire foreign income tax amount paid or accrued by DE1, and under paragraph (b)(2)(iii)(A) of this section, CFC1's allocable foreign income will be equal to DE1's entire foreign income.
(C) In U.S. taxable year 1, CFC1 has an aggregate basis difference of 9u (the 9u cost recovery amount with respect to Asset A for U.S. taxable year 1). However, because the foreign taxable year of DE1, the foreign payor, will not end between July 1 and December 31, there will not be a foreign income tax amount for U.S. taxable year 1. Because the foreign income tax amount considered paid or accrued by CFC1 for U.S. taxable year 1 is zero, under paragraph (b)(2)(iv) of this section, the disqualified tax amount for U.S. taxable year 1 of CFC1 is also zero. Furthermore, because the disqualified tax amount is zero, under paragraph (c)(2)(i) of this section, CFC1 has an aggregate basis difference carryover equal to 9u, the entire amount of the aggregate basis difference for U.S. taxable year 1. Under paragraph (c)(1) of this section, the 9u aggregate basis difference carryover is taken into account in computing CFC1's aggregate basis difference for U.S. taxable year 2. Accordingly, in U.S. taxable year 2, CFC1 has an aggregate basis difference of 27u (18u cost recovery amount for U.S. taxable year 2, plus 9u aggregate basis difference carryover from U.S. taxable year 1).
(d)Applicability dates. This section applies to CAAs occurring on or after March 23, 2020. Taxpayers may, however, choose to apply this section before the date this section is applicable provided that they (along with any persons that are related (within the meaning of section 267(b) or 707(b)) to the taxpayer)-
(1) Consistently apply this section, § 1.704-1(b)(4) (viii)(c)(4)(v) through (vii), § 1.901(m)-1 , and §§ 1.901(m)-4 through 1.901(m)-8 (excluding § 1.901(m)-4(e) ) to all CAAs occurring on or after January 1, 2011, and consistently apply § 1.901(m)-2 (excluding § 1.901(m)-2(d) ) to all CAAs occurring on or after December 7, 2016, on any original or amended tax return for each taxable year for which the application of the provisions listed in this paragraph (d)(1) affects the tax liability and for which the statute of limitations does not preclude assessment or the filing of a claim for refund, as applicable
(2) File all tax returns described in paragraph (d)(1) of this section for any taxable year ending on or before March 23, 2020, no later than March 23, 2021; and
(3) Make appropriate adjustments to take into account deficiencies that would have resulted from the consistent application under paragraph (d)(1) of this section for taxable years that are not open for assessment.

26 C.F.R. §1.901(m)-3

T.D. 9895, 85 FR 16252 , Mar. 23, 2020
T.D. 9895, 85 FR 16252, 3/23/2020