(a) In general. This section provides rules for determining for each RFA the basis difference that arises as a result of a CAA. A basis difference is computed separately with respect to each foreign income tax for which an asset subject to a CAA is an RFA. Paragraph (b) of this section provides the general rule for determining basis difference that references only U.S. basis in the RFA. Paragraph (c) of this section provides for an election to determine basis difference by reference to foreign basis and sets forth the procedures for making the election. Paragraph (d) of this section provides special rules for determining basis difference in the case of a section 743(b) CAA. Paragraph (e) of this section provides a special rule for determining basis difference in an RFA with respect to a CAA to which paragraphs (b) through (d) of this section do not apply. Paragraph (f) of this section provides examples illustrating the rules of this section, and paragraph (g) of this section provides applicability dates.

(b) General rule. Except as otherwise provided in paragraphs (c), (d), and (e) of this section, basis difference is the U.S. basis in the RFA immediately after the CAA, less the U.S. basis in the RFA immediately before the CAA. Basis difference is an attribute that attaches to an RFA.

(c) Foreign basis election. (1) An election (foreign basis election) may be made to apply section 901(m)(3)(C)(i)(II) by reference to the foreign basis immediately after the CAA instead of the U.S. basis immediately before the CAA. Accordingly, if a foreign basis election is made, basis difference is the U.S. basis in the RFA immediately after the CAA, less the foreign basis in the RFA immediately after the CAA. For this purpose, the foreign basis immediately after the CAA takes into account any adjustment to that foreign basis resulting from the CAA for purposes of the foreign income tax.

(2) Except as otherwise provided in this paragraph (c), a foreign basis election is made by the RFA owner (U.S.). If, however, the RFA owner (U.S.) is a partnership, each partner in the partnership (and not the partnership) may independently make a foreign basis election. In the case of one or more tiered partnerships, the foreign basis election is made at the level at which a partner is not also a partnership.

(3) The foreign basis election may be made separately for each CAA, and with respect to each foreign income tax and each foreign payor. For purposes of making the foreign basis election, all CAAs that are part of an aggregated CAA transaction are treated as a single CAA. Furthermore, for purposes of making the foreign basis election, if foreign law imposes tax on the combined income (within the meaning of § 1.901-2(f)(3)(ii)) of two or more foreign payors, all foreign payors whose items of income, deduction, gain, or loss for U.S. income tax purposes are included in the U.S. taxable income or earnings and profits of a single section 901(m) payor are treated as a single foreign payor.

(4) A foreign basis election is made by using foreign basis to determine basis difference for purposes of computing a disqualified tax amount and an aggregate basis difference carryover for the U.S. taxable year, as provided under § 1.901(m)-3. A separate statement or form evidencing the foreign basis election need not be filed. Except as provided in paragraphs (c)(5) and (6) of this section, in order for a foreign basis election to be effective, the election must be reflected on a timely filed original federal income tax return (taking into account extensions) for the first U.S. taxable year that the foreign basis election is relevant to the computation of any amounts reported on such return, including on any required schedules.

(5) If the RFA owner (U.S.) is a partnership, a foreign basis election reflected on a partner's timely filed amended federal income tax return is also effective if all of the following conditions are satisfied:

(i) The partner's timely filed original federal income tax return (taking into account extensions) for the first U.S. taxable year of the partner in which a foreign basis election is relevant to the computation of any amounts reported on such return, including on any required schedules, does not reflect the application of section 901(m);

(ii) The information provided by the partnership to the partner for purposes of applying section 901(m) and any information required to be reported by the partnership is based solely on computations that use foreign basis to determine basis difference; and

(iii) Before the due date of the original federal income tax return described in paragraph (c)(5)(i) of this section, the partner delegated the authority to the partnership to choose whether to provide the partner with information to apply section 901(m) using foreign basis, either pursuant to a written partnership agreement (within the meaning of § 1.704-1(b)(2)(ii)(h)) or written notice provided by the partner to the partnership.

(6) If, pursuant to paragraph (g)(3) of this section, a taxpayer chooses to have this section apply to CAAs occurring on or after January 1, 2011, a foreign basis election will be effective if the election is reflected on a timely filed amended federal income tax return (or tax returns, as applicable) filed no later than March 23, 2021.

(7) The foreign basis election is irrevocable. Relief under § 301.9100-1 is not available for the foreign basis election.

(d) Determination of basis difference in a section 743(b) CAA—(1) In general. Except as provided in paragraphs (d)(2) and (e) of this section, if there is a section 743(b) CAA, basis difference is the resulting basis adjustment under section 743(b) that is allocated to the RFA under section 755.

(2) Foreign basis election. If a foreign basis election is made with respect to a section 743(b) CAA, then, for purposes of paragraph (d)(1) of this section, the section 743(b) adjustment is determined by reference to the foreign basis of the RFA, determined immediately after the CAA.

(e) Determination of basis difference in an RFA with respect to a CAA with respect to which paragraphs (b), (c), and (d) of this section do not apply. For CAAs occurring on or after January 1, 2011, and before July 21, 2014, other than CAAs occurring before July 21, 2014, resulting from an entity classification election made under § 301.7701-3 of this chapter that is filed on or after July 29, 2014, and that is effective on or before July 21, 2014, basis difference in an RFA with respect to the CAA is the amount of any basis difference (within the meaning of section 901(m)(3)(C)(i)) that had not been taken into account under section 901(m)(3)(B) either as of July 21, 2014, or, in the case of an entity classification election made under § 301.7701-3 of this chapter that is filed on or after July 29, 2014, and that is effective on or before July 21, 2014, before the transactions that are deemed to occur under § 301.7701-3(g) as a result of the change in classification.

(f) Examples. The following examples illustrate the rules of this section:

(1) Example 1: Scope of basis choice; identifying separate CAAs, RFA owners (U.S.), and foreign payors in an aggregated CAA transaction—(i) Facts. CFC1 wholly owns CFC2, both of which are applicable foreign corporations, organized in Country F, and treated as corporations for Country F tax purposes. CFC1 also wholly owns DE1, and DE1 wholly owns DE2. DE1 and DE2 are entities organized in Country F treated as corporations for Country F tax purposes and as disregarded entities for U.S. income tax purposes. Country F imposes a single tax that is a foreign income tax. All of the stock of CFC1 is acquired in a qualified stock purchase (within the meaning of section 338(d)(3)) to which section 338(a) applies for both CFC1 and CFC2. For Country F tax purposes, the transaction is treated as an acquisition of the stock of CFC1.

(ii) Result. (A) The acquisition of CFC1 gives rise to four separate CAAs described in § 1.901(m)-2. Under § 1.901(m)-2(b)(1), the acquisition of the stock of CFC1 and the deemed acquisition of the stock of CFC2 under section 338(h)(3)(B) are each a section 338 CAA. Furthermore, because the deemed acquisition of the assets of each of DE1 and DE2 for U.S. income tax purposes is disregarded for Country F tax purposes, the deemed acquisitions are CAAs under § 1.901(m)-2(b)(2). Because the four CAAs occurred pursuant to a plan, under § 1.901(m)-1(a)(3), all of the CAAs 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 the assets of DE1 and DE2 that are RFAs. CFC2 is the RFA owner (U.S.) with respect to its assets that are RFAs. Under § 1.901(m)-1(a)(28), CFC1, CFC2, DE1, and DE2 are each a foreign payor for Country F tax purposes.

(B) Under paragraph (c) of this section, a foreign basis election may be made by the RFA owner (U.S.). The election is made separately with respect to each CAA (for this purpose, treating all CAAs that are part of an aggregated CAA transaction as a single CAA) and with respect to each foreign income tax and foreign payor. Thus, in this case, CFC1 can make a separate foreign basis election for one or more of the following three groups of RFAs: RFAs that are relevant in determining foreign income of CFC1; RFAs that are relevant in determining foreign income of DE1; and RFAs that are relevant in determining foreign income of DE2. Furthermore, CFC2 can make a foreign basis election for all of its RFAs that are relevant in determining its foreign income.

(2) Example 2: Scope of basis choice; RFA owner (U.S.) is a partnership—(i) Facts. USPS is a domestic partnership for which a section 754 election is in effect. USPS owns two assets, the stock of DE1 and DE2. DE1 is an entity organized in Country X and treated as a corporation for Country X tax purposes. DE2 is an entity organized in Country Y and treated as a corporation for Country Y tax purposes. DE1 and DE2 are disregarded entities. Country X and Country Y each impose a single tax that is a foreign income tax. US1 and US2, unrelated domestic corporations, and FP, a foreign person unrelated to US1 and US2, acquire partnership interests in USPS from existing partners of USPS pursuant to the same plan.

(ii) Result. Under § 1.901(m)-2(b)(3), the acquisitions of the partnership interests in USPS by US1, US2, and FP each give rise to separate section 743(b) CAAs, but under § 1.901(m)-1(a)(3), they are treated as an aggregated CAA transaction because they occur as part of a plan. Under § 1.901(m)-1(a)(37), USPS is the RFA owner (U.S.) with respect to the assets of DE1 and DE2 that are RFAs. Under § 1.901(m)-1(a)(28), DE1 is a foreign payor for Country X tax purposes, and DE2 is a foreign payor for Country Y tax purposes. Because the RFA owner (U.S.) is a partnership, paragraph (c)(2) of this section provides that US1, US2, and FP (the relevant partners in USPS) separately choose whether to make a foreign basis election for purposes of determining basis difference. Furthermore, under paragraph (c)(3) of this section, the choice to make the election is made separately by each partner with respect to each foreign payor. Thus, in this case, each partner may make separate elections for the RFAs that are relevant in determining foreign income of DE1 for Country X tax purposes and the RFAs that are relevant in determining foreign income of DE2 for Country Y tax purposes.

(g) Applicability dates. (1) Except as provided in paragraph (g)(2) of this section, this section applies to CAAs occurring on or after March 23, 2020.

(2) Paragraphs (a), (b), and (d)(1) of this section apply to CAAs occurring on or after July 21, 2014, and to CAAs occurring before that date resulting from an entity classification election made under § 301.7701-3 that is filed on or after July 29, 2014, and that is effective on or before July 21, 2014. Paragraph (e) of this section applies to CAAs occurring on or after January 1, 2011, and before July 21, 2014, other than CAAs occurring before July 21, 2014, resulting from an entity classification election made under § 301.7701-3 of this chapter that is filed on or after July 29, 2014, and that is effective on or before July 21, 2014. Taxpayers may, however, consistently apply paragraph (d)(1) of this section to all section 743(b) CAAs occurring on or after January 1, 2011. For this purpose, persons that are related (within the meaning of section 267(b) or 707(b)) will be treated as a single taxpayer.

(3) Taxpayers may, however, choose to apply provisions in this section before the date such provisions are applicable pursuant to paragraph (g)(1) or (2) of this section, provided that they (along with any persons that are related (within the meaning of section 267(b) or 707(b)) to the taxpayer)—

(i) Consistently apply this section (excluding paragraph (e) of this section), § 1.704-1(b)(4)(viii)(c)(4)(v) through (vii), § 1.901(m)-1, § 1.901(m)-3, and §§ 1.901(m)-5 through 1.901(m)-8 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 (g)(3)(i) 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;

(ii) File all tax returns described in paragraph (g)(3)(i) of this section for any taxable year ending on or before March 23, 2020, no later than March 23, 2021; and

(iii) Make appropriate adjustments to take into account deficiencies that would have resulted from the consistent application under paragraph (g)(3)(i) of this section for taxable years that are not open for assessment.