(Slip Opinion) OCTOBER TERM, 2012 1 

Syllabus 

NOTE: Where it is feasible, a syllabus (headnote) will be released, as is

being done in connection with this case, at the time the opinion is issued.

The syllabus constitutes no part of the opinion of the Court but has been

prepared by the Reporter of Decisions for the convenience of the reader. 

See United States v. Detroit Timber & Lumber Co., 200 U. S. 321, 337. 

SUPREME COURT OF THE UNITED STATES 

Syllabus 

PPL CORP. ET AL. v. COMMISSIONER OF INTERNAL 

REVENUE
 

CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR 

THE THIRD CIRCUIT 

No. 12–43. Argued February 20, 2013—Decided May 20, 2013 

In 1997, the United Kingdom (U. K.), newly under Labour Party rule, 

imposed a one-time “windfall tax” on 32 U. K. companies privatized

between 1984 and 1996 by the Conservative government. The companies had been sold to private parties through an initial sale of

shares, known as a “flotation.” Some of the companies were required 

to continue providing services for a fixed period at the same rates 

they had offered under government control. Many of those companies 

became dramatically more efficient and earned substantial profits in 

the process.

Petitioner PPL Corporation (PPL), part owner of a privatized U. K. 

company subject to the windfall tax, claimed a credit for its share of 

the bill in its 1997 federal income-tax return, relying on Internal

Revenue Code §901(b)(1), which states that any “income, war profits, 

and excess profits taxes” paid overseas are creditable against U. S. 

income taxes. Treasury Regulation §1.901–2(a)(1) interprets this section to mean that a foreign tax is creditable if its “predominant character” “is that of an income tax in the U. S. sense.” The Commissioner of Internal Revenue (Commissioner) rejected PPL’s claim, but the 

Tax Court held that the U. K. windfall tax was creditable for U. S. 

tax purposes under §901. The Third Circuit reversed. 

Held: The U. K. tax is creditable under §901. Pp. 4–14.

(a) Treasury Regulation §1.901–2, which codifies longstanding doctrine dating back to Biddle v. Commissioner, 302 U. S. 573, 578–579 

(1938), provides the relevant legal standard. First, a tax’s “predominant character,” or the normal manner in which a tax applies, is controlling. See id., at 579. Thus, a foreign tax that operates as an income, war profits, or excess profits tax for most taxpayers is generally 
 

 

 

 

2 PPL CORP. v. COMMISSIONER 

Syllabus 

creditable. Second, foreign tax creditability depends not on the way a

foreign government characterizes its tax but on whether the tax, if 

enacted in the U. S., would be an income, war profits, or excess profits tax. See §1.901–2(a)(1)(ii). Giving further form to these principles, §1.901–2(a)(3)(i) explains that a foreign tax’s predominant character is that of a U. S. income tax “[i]f . . . the foreign tax is likely to 

reach net gain in the normal circumstances in which it applies.”

Three tests set forth in the regulations provide guidance in making 

this assessment, see §1.901–2(b)(1). The tests indicate that net gain

consists of realized gross receipts reduced by significant costs and expenses attributable to such gross receipts, in combination known as 

net income. A foreign tax that reaches net income, or profits, is creditable. Pp. 4–7.

(b) The U. K. windfall tax’s predominant character is that of an excess profits tax, a category of income tax in the U. S. sense. The Labour government’s conception of “profit-making value” as a backwardlooking analysis of historic profits is not a typical valuation 

method. Rather, it is a tax on realized net income disguised as a

tax on the difference between two values, one of which is a fictitious 

value calculated using an imputed price-to-earnings ratio. The substance of the windfall tax confirms this conclusion. When rearranged, the U. K’s formula demonstrates that the windfall tax is economically equivalent to the difference between the profits each 

company actually earned and the amount the Labour government believed it should have earned given its flotation value. For most of the 

relevant companies, the U. K. formula’s substantive effect was to impose a 51.71 percent tax on all profits above a threshold, a classic excess profits tax. The Commissioner claims that any algebraic rearrangement is improper because U. S. courts must take the foreign tax

rate as written and accept whatever tax base the foreign tax purports 

to adopt. But such a rigid construction cannot be squared with the

black-letter principle that “tax law deals in economic realities, not legal abstractions.” Commissioner v. Southwest Exploration Co., 350 

U. S. 308, 315. Given the artificiality of the U. K.’s calculation method, this Court follows substance over form and recognizes that the 

windfall tax is nothing more than a tax on actual profits above a 

threshold. Pp. 7–11.

(c) The Commissioner’s additional arguments in support of his position are similarly unpersuasive. Pp. 11–14. 

665 F. 3d 60, reversed. 

THOMAS, J., delivered the opinion for a unanimous Court. 

SOTOMAYOR, J., filed a concurring opinion. 
 

 

_________________ 

_________________ 

Cite as: 569 U. S. ____ (2013) 1 

Opinion of the Court 

NOTICE: This opinion is subject to formal revision before publication in the

preliminary print of the United States Reports. Readers are requested to

notify the Reporter of Decisions, Supreme Court of the United States, Washington, D. C. 20543, of any typographical or other formal errors, in order

that corrections may be made before the preliminary print goes to press. 

SUPREME COURT OF THE UNITED STATES 

No. 12–43 

PPL CORPORATION AND SUBSIDIARIES, PETITIONERS v. COMMISSIONER OF INTERNAL REVENUE 

ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF 

APPEALS FOR THE THIRD CIRCUIT 

[May 20, 2013] 

JUSTICE THOMAS delivered the opinion of the Court. 

In 1997, the United Kingdom (U. K.) imposed a one-time

“windfall tax” on 32 U. K. companies privatized between 

1984 and 1996. This case addresses whether that tax 

is creditable for U. S. tax purposes. Internal Revenue Code 

§901(b)(1) states that any “income, war profits, and excess 

profits taxes” paid overseas are creditable against U. S.

income taxes. 26 U. S. C. §901(b)(1). Treasury Regulations interpret this section to mean that a foreign tax is

creditable if its “predominant character” “is that of an 

income tax in the U. S. sense.” Treas. Reg. §1.901–

2(a)(1)(ii), 26 CFR §1.901–2(a)(1) (1992). Consistent with 

precedent and the Tax Court’s analysis below, we apply 

the predominant character test using a commonsense 

approach that considers the substantive effect of the tax. 

Under this approach, we hold that the U. K. tax is creditable under §901 and reverse the judgment of the Court of 

Appeals for the Third Circuit. 

I 

A 

During the 1980’s and 1990’s, the U. K.’s Conservative 
 

 

2 PPL CORP. v. COMMISSIONER 

Opinion of the Court 

Party controlled Parliament and privatized a number of 

government-owned companies. These companies were

sold to private parties through an initial sale of shares, 

known as a “flotation.” As part of privatization, many companies were required to continue providing services at the 

same rates they had offered under government control 

for a fixed period, typically their first four years of private 

operation. As a result, the companies could only increase 

profits during this period by operating more efficiently. 

Responding to market incentives, many of the companies

became dramatically more efficient and earned substantial

profits in the process.

The U. K.’s Labour Party, which had unsuccessfully 

opposed privatization, used the companies’ profitability as

a campaign issue against the Conservative Party. In part

because of campaign promises to tax what it characterized 

as undue profits, the Labour Party defeated the Conservative Party at the polls in 1997. Prior to coming to power,

Labour Party leaders hired accounting firm Arthur Andersen to structure a tax that would capture excess, or “windfall,” profits earned during the initial years in which the 

companies were prohibited from increasing rates. Parliament eventually adopted the tax, which applied only to

the regulated companies that were prohibited from raising 

their rates. See Finance (No. 2) Act, 1997, ch. 58, pt. I, 

cls. 1 and 2(5) (Eng.) (U. K. Windfall Tax Act). It imposed

a 23 percent tax on any “windfall” earned by such companies. Id., cl. 1(2). A separate schedule “se[t] out how to

quantify the windfall from which a company was benefitting.” Id., cl. 1(3). See id., sched. 1. 

In the proceedings below, the parties stipulated that the

following formula summarizes the tax imposed by the 

Labour Party:

P

Tax = 23% ൤൬365 × ൬ ൰ × 9൰ − FV൨ D

D equals the number of days a company was subject to 
 

 

Cite as: 569 U. S. ____ (2013) 3 

Opinion of the Court 

rate regulation (also known as the “initial period”), P

equals the total profits earned during the initial period,

and FV equals the flotation value, or market capitalization 

value after sale. For 27 of the 32 companies subject to 

the tax, the number of days in the initial period was 1,461

days (or four years). Of the remaining five companies, one

had no tax liability because it did not earn any windfall 

profits. Three had initial periods close to four years 

(1,463, 1,456, and 1,380 days). The last was privatized

shortly before the Labour Party took power and had an

initial period of only 316 days.

The number 9 in the formula was characterized as a 

price-to-earnings ratio and was selected because it represented the lowest average price-to-earnings ratio of the 32 

companies subject to the tax during the relevant period.1 

See id., sched. 1, §1, cl. 2(3); Brief for Respondent 7. The 

statute expressly set its value, and that value was the 

same for all companies. U. K. Windfall Tax Act, sched. 1, 

§1, cl. 2(3). The only variables that changed in the windfall tax formula for all the companies were profits (P) and 

flotation value (FV); the initial period (D) varied for only a 

few of the companies subject to the tax. The Labour government asserted that the term [365 × (P ⁄ D) × 9] represented what the flotation value should have been given the 

assumed price-to-earnings ratio of 9. Thus, it claimed 

(and the Commissioner here reiterates) that the tax was 

simply a 23 percent tax on the difference between what 

the companies’ flotation values should have been and what 

they actually were. 

B 

Petitioner PPL Corporation (PPL) was an owner, 

—————— 

1A price-to-earnings ratio “is defined as the stock price divided by

annual earnings per share. It is typically calculated by dividing the 

current stock price by the sum of the previous four quarters of earnings.” 3 New Palgrave Dictionary of Money & Finance 176 (1992). 
 

 

4 PPL CORP. v. COMMISSIONER 

Opinion of the Court 

through a number of subsidiaries, of 25 percent of South 

Western Electricity plc, 1 of 12 government-owned electric companies that were privatized in 1990 and that were 

subject to the tax. See 135 T. C. 304, 307, App. (2010) 

(diagram of PPL corporate structure in 1997). South 

Western Electricity’s total U. K. windfall tax burden was 

£90,419,265. In its 1997 federal income-tax return, PPL 

claimed a credit under §901 for its share of the bill. The 

Commissioner of Internal Revenue (Commissioner) rejected

the claim, but the Tax Court held that the U. K. windfall tax was creditable for U. S. tax purposes under §901. 

See id., at 342. The Third Circuit reversed. 665 F. 3d 60, 

68 (2011). We granted certiorari, 568 U. S. ___ (2012), to 

resolve a Circuit split concerning the windfall tax’s creditability under §901. Compare 665 F. 3d, at 68, with 

Entergy Corp. & Affiliated Subsidiaries v. Commissioner, 

683 F. 3d 233, 239 (CA5 2012). 

II 

Internal Revenue Code §901(b)(1) provides that “[i]n the

case of . . . a domestic corporation, the amount of any 

income, war profits, and excess profits taxes paid or accrued during the taxable year to any foreign country or to 

any possession of the United States” shall be creditable.2 

Under relevant Treasury Regulations, “[a] foreign levy is 

an income tax if and only if . . . [t]he predominant character of that tax is that of an income tax in the U. S. sense.” 

26 CFR §1.901–2(a)(1). The parties agree that Treasury

Regulation §1.901–2 applies to this case. That regulation

codifies longstanding doctrine dating back to Biddle v. 

—————— 

2Prior to enactment of what is now §901, income earned overseas was

subject to taxes not only in the foreign country but also in the United

States. See Burnet v. Chicago Portrait Co., 285 U. S. 1, 7 (1932). The 

relevant text making “income, war-profits and excess-profits taxes” 

creditable has not changed since 1918. See Revenue Act of 1918, 

§§222(a)(1), 238(a), 40 Stat. 1073, 1080. 
Cite as: 569 U. S. ____ (2013) 5 

Opinion of the Court 

Commissioner, 302 U. S. 573, 578–579 (1938), and provides the relevant legal standard.

The regulation establishes several principles relevant to

our inquiry. First, the “predominant character” of a tax,

or the normal manner in which a tax applies, is controlling. See id., at 579 (“We are here concerned only with

the ‘standard’ or normal tax”). Under this principle, a foreign tax that operates as an income, war profits, or excess

profits tax in most instances is creditable, even if it may 

affect a handful of taxpayers differently. Creditability is

an all or nothing proposition. As the Treasury Regulations confirm, “a tax either is or is not an income tax, in its 

entirety, for all persons subject to the tax.” 26 CFR 

§1.901–2(a)(1). 

Second, the way a foreign government characterizes its

tax is not dispositive with respect to the U. S. creditability 

analysis. See §1.901–2(a)(1)(ii) (foreign tax creditable if 

predominantly “an income tax in the U. S. sense”). In 

Biddle, the Court considered the creditability of certain

U. K. taxes on stock dividends under the substantively 

identical predecessor to §901. The Court recognized that

“there is nothing in [the statute’s] language to suggest

that in allowing the credit for foreign tax payments, a 

shifting standard was adopted by reference to foreign 

characterizations and classifications of tax legislation.” 

302 U. S., at 578–579. See also United States v. Goodyear 

Tire & Rubber Co., 493 U. S. 132, 145 (1989) (noting in

interpreting 26 U. S. C. §902 that Biddle is particularly

applicable “where a contrary interpretation would leave” 

tax interpretation “to the varying tax policies of foreign

tax authorities”); Heiner v. Mellon, 304 U. S. 271, 279, and 

n. 7 (1938) (state-law definitions generally not controlling 

in federal tax context). Instead of the foreign government’s characterization of the tax, the crucial inquiry is

the tax’s economic effect. See Biddle, supra, at 579 (inquiry is “whether [a tax] is the substantial equivalent of 
 

 

 

 

 

 

6 PPL CORP. v. COMMISSIONER 

Opinion of the Court 

payment of the tax as those terms are used in our own

statute”). In other words, foreign tax creditability depends

on whether the tax, if enacted in the U. S., would be an 

income, war profits, or excess profits tax.

Giving further form to these principles, Treasury Regulation §1.901–2(a)(3)(i) explains that a foreign tax’s predominant character is that of a U. S. income tax “[i]f . . . 

the foreign tax is likely to reach net gain in the normal 

circumstances in which it applies.” The regulation then 

sets forth three tests for assessing whether a foreign tax 

reaches net gain. A tax does so if, “judged on the basis of 

its predominant character, [it] satisfies each of the realization, gross receipts, and net income requirements set forth 

in paragraphs (b)(2), (b)(3) and (b)(4), respectively, of this 

section.” §1.901–2(b)(1).3 The tests indicate that net gain

(also referred to as net income) consists of realized gross 

receipts reduced by significant costs and expenses attributable to such gross receipts. A foreign tax that reaches 

—————— 

3The relevant provisions provide as follows: 

“A foreign tax satisfies the realization requirement if, judged on the 

basis of its predominant character, it is imposed—(A) Upon or subsequent to the occurrence of events (‘realization events’) that would result

in the realization of income under the income tax provisions of the

Internal Revenue Code.” 26 CFR §1.901–2(b)(2)(i). 

“A foreign tax satisfies the gross receipts requirement if, judged on the

basis of its predominant character, it is imposed on the basis of—(A)

Gross receipts; or (B) Gross receipts computed under a method that is

likely to produce an amount that is not greater than fair market value.”

§1.901–2(b)(3)(i). 

“A foreign tax satisfies the net income requirement if, judged on the

basis of its predominant character, the base of the tax is computed by 

reducing gross receipts . . . to permit—(A) Recovery of the significant 

costs and expenses (including significant capital expenditures) attributable, under reasonable principles, to such gross receipts; or (B) 

Recovery of such significant costs and expenses computed under a 

method that is likely to produce an amount that approximates, or is

greater than, recovery of such significant costs and expenses.” §1.901– 

2(b)(4)(i). 
 

Cite as: 569 U. S. ____ (2013) 7 

Opinion of the Court 

net income, or profits, is creditable. 

III 

A 

It is undisputed that net income is a component of the

U. K.’s “windfall tax” formula. See Brief for Respondent 

23 (“The windfall tax takes into account a company’s profits during its four-year initial period”). Indeed, annual 

profit is a variable in the tax formula. U. K. Windfall Tax 

Act, sched. 1, §1, cls. 2(2) and 5. It is also undisputed that

there is no meaningful difference for our purposes in the

accounting principles by which the U. K. and the U. S.

calculate profits. See Brief for Petitioners 47. The disagreement instead centers on how to characterize the tax

formula the Labour Party adopted.

The Third Circuit, following the Commissioner’s lead, 

believed it could look no further than the tax formula that 

the Parliament enacted and the way in which the Labour 

government characterized it. Under that view, the windfall tax must be considered a tax on the difference between 

a company’s flotation value (the total amount investors

paid for the company when the government sold it) and 

an imputed “profit-making value,” defined as a company’s 

“average annual profit during its ‘initial period’ . . . times

9, the assumed price-to-earnings ratio.” 665 F. 3d, at 65. 

So characterized, the tax captures a portion of the difference between the price at which each company was sold 

and the price at which the Labour government believed 

each company should have been sold given the actual

profits earned during the initial period. Relying on this 

characterization, the Third Circuit believed the windfall 

tax failed at least the Treasury Regulation’s realization

and gross receipts tests because it reached some artificial 

form of valuation instead of profits. See id., at 67, and 

n. 3. 

In contrast, PPL’s position is that the substance of the 
 

 

8 PPL CORP. v. COMMISSIONER 

Opinion of the Court 

windfall tax is that of an income tax in the U. S. sense. 

While recognizing that the tax ostensibly is based on the

difference between two values, it argues that every “variable” in the windfall tax formula except for profits and

flotation value is fixed (at least with regard to 27 of the 32

companies). PPL emphasizes that the only way the Labour government was able to calculate the imputed “profitmaking value” at which it claimed companies should have 

been privatized was by looking after the fact at the actual 

profits earned by each company. In PPL’s view, it matters 

not how the U. K. chose to arrange the formula or what it 

claimed to be taxing, because a tax based on profits above

some threshold is an excess profits tax, regardless of how 

it is mathematically arranged or what labels foreign law 

places on it. PPL, thus, contends that the windfall taxes it 

paid meet the Treasury Regulation’s tests and are creditable under §901.

We agree with PPL and conclude that the predominant 

character of the windfall tax is that of an excess profits 

tax, a category of income tax in the U. S. sense. It is 

important to note that the Labour government’s conception of “profit-making value” as a backward-looking analysis of historic profits is not a recognized valuation method; 

instead, it is a fictitious value calculated using an imputed 

price-to-earnings ratio. At trial, one of PPL’s expert witnesses explained that “‘9 is not an accurate P/E multiple, 

and it is not applied to current or expected future earnings.’” 135 T. C., at 326, n. 17 (quoting testimony). Instead, the windfall tax is a tax on realized net income 

disguised as a tax on the difference between two values, 

one of which is completely fictitious. See App. 251, Report

¶1.7 (“[T]he value in profit making terms described in the 

wording of the act . . . is not a real value: it is rather a

construct based on realised profits that would not have

been known at the date of privatisation”).

The substance of the windfall tax confirms the accuracy 
 

 

 

 

Cite as: 569 U. S. ____ (2013) 9 

Opinion of the Court 

of this observation. As already noted, the parties stipulated

that the windfall tax could be calculated as follows: 

P

Tax = 23% ൤൬365 × ൬ ൰ × 9൰ − FV൨ D

This formula can be rearranged algebraically to the following formula, which is mathematically and substantively 

identical:4 

Tax = ൤

(365 × 9 × 23%)൨ × ൜P − ൤FV × (D

) ൨ൠ D 365 × 9

The next step is to substitute the actual number of days

for D. For 27 of the 32 companies subject to the windfall

tax, the number of days was identical, 1,461 (or four 

years). Inserting that amount for D in the formula yields 

the following: 

(365 × 9 × 23%) 1,461 Tax = ൤ 1,461 ൨ × ൜P − ൤FV × (365 × 9) ൨ൠ
 

Simplifying the formula by multiplying and dividing numbers reduces the formula to: 

FV

Tax = 51.71% × ൤P − ൬ ൰ × 4.0027൨ 9

As noted, FV represents the value at which each company

was privatized. FV is then divided by 9, the arbitrary

“price-to-earnings ratio” applied to every company. The 

—————— 

4The rearrangement requires only basic algebraic manipulation. 

First, because order of operations does not matter for multiplication

and division, the formula is rearranged to the following: 

Tax = 23%	ቂ൬365 × 9 × ቀୈ

୔

ቁ൰ − FVቃ

Next, everything outside the brackets is multiplied by ቂ

(ଷ଺ହ×ଽ)ቃ,	and ୈ ୈ everything inside the brackets is multiplied by the inverse, ቂ

(ଷ଺ହ×ଽ)ቃ.

The effect is the same as multiplication by the number one (since

ቄቂ(ଷ଺ହ×ଽ)ቃ × ቂ ୈ ቃቅ = 1). That multiplication yields the formula in the ୈ (ଷ଺ହ×ଽ)

text. 
 

 

10 PPL CORP. v. COMMISSIONER 

Opinion of the Court 

economic effect is to convert flotation value into the profits 

a company should have earned given the assumed priceto-earnings ratio. See 135 T. C., at 327 (“‘In effect, the 

way the tax works is to say that the amount of profits

you’re allowed in any year before you’re subject to tax is 

equal to one-ninth of the flotation price. After that, profits 

are deemed excess, and there is a tax’” (quoting testimony

from the treasurer of South Western Electricity plc)). The 

annual profits are then multiplied by 4.0027, giving the

total “acceptable” profits (as opposed to windfall profit)

that each company’s flotation value entitled it to earn 

during the initial period given the artificial price-toearnings ratio of 9. This fictitious amount is finally subtracted from actual profits, yielding the excess profits,

which were taxed at an effective rate of 51.71 percent. 

The rearranged tax formula demonstrates that the 

windfall tax is economically equivalent to the difference

between the profits each company actually earned and the 

amount the Labour government believed it should have 

earned given its flotation value. For the 27 companies 

that had 1,461-day initial periods, the U. K. tax formula’s

substantive effect was to impose a 51.71 percent tax on all

profits earned above a threshold. That is a classic excess 

profits tax. See, e.g., Act of Mar. 3, 1917, ch. 159, Tit. II, 

§201, 39 Stat. 1000 (8 percent tax imposed on excess profits exceeding the sum of $5,000 plus 8 percent of invested

capital).

Of course, other algebraic reformulations of the windfall

tax equation are possible. See 665 F. 3d, at 66; Brief for 

Anne Alstott et al. as Amici Curiae 21–23 (Alstott Brief).

The point of the reformulation is not that it yields a particular percentage (51.75 percent for most of the companies). Rather, the algebraic reformulations illustrate the 

economic substance of the tax and its interrelationship

with net income. 

The Commissioner argues that any algebraic rear­
 

Cite as: 569 U. S. ____ (2013) 11 

Opinion of the Court 

rangement is improper, asserting that U. S. courts must 

take the foreign tax rate as written and accept whatever

tax base the foreign tax purports to adopt. Brief for Respondent 28. As a result, the Commissioner claims that 

the analysis begins and ends with the Labour government’s choice to characterize its tax base as the difference 

between “profit-making value” and flotation value. Such a 

rigid construction is unwarranted. It cannot be squared

with the black-letter principle that “tax law deals in economic realities, not legal abstractions.” Commissioner v. 

Southwest Exploration Co., 350 U. S. 308, 315 (1956). 

Given the artificiality of the U. K.’s method of calculating

purported “value,” we follow substance over form and 

recognize that the windfall tax is nothing more than a tax 

on actual profits above a threshold. 

B 

We find the Commissioner’s other arguments unpersuasive as well. First, the Commissioner attempts to buttress 

the argument that the windfall tax is a tax on value by 

noting that some U. S. gift and estate taxes use actual, 

past profits to estimate value. Brief for Respondent 17–18

(citing 26 CFR §20.2031–3 (2012) and 26 U. S. C. §2032A).

This argument misses the point. In the case of valuation 

for gift and estate taxes, past income may be used to estimate future income streams. But, it is future revenueearning potential, reduced to market value, that is subject

to taxation. The windfall profits tax, by contrast, undisputedly taxed past, realized net income alone. 

The Commissioner contends that the U. K. was not 

trying to establish valuation as of the 1997 date on which

the windfall tax was enacted but instead was attempting

to derive a proper flotation valuation as of each company’s

flotation date. Brief for Respondent 21. The Commissioner 

asserts that there was no need to estimate future income (as in the case of the gift or estate recipient) because 
 

 

12 PPL CORP. v. COMMISSIONER 

Opinion of the Court 

actual revenue numbers for the privatized companies were

available. Ibid. That argument also misses the mark. It 

is true, of course, that the companies might have been 

privatized at higher flotation values had the government 

recognized how efficient—and thus how profitable—the 

companies would become. But, the windfall tax requires

an underlying concept of value (based on actual ex post 

earnings) that would be alien to any valuer. Taxing actual, realized net income in hindsight is not the same as

considering past income for purposes of estimating future 

earning potential.

The Commissioner’s reliance on Example 3 to the

Treasury Regulation’s gross receipts test is also misplaced. 

Id., at 37–38; 26 CFR §1.901–2(b)(3)(ii), Ex. 3. That example posits a petroleum tax in which “gross receipts from 

extraction income are deemed to equal 105 percent of the

fair market value of petroleum extracted. This computation is designed to produce an amount that is greater than

the fair market value of actual gross receipts.” Ibid. 

Under the example, a tax based on inflated gross receipts

is not creditable. 

The Third Circuit believed that the same type of algebraic rearrangement used above could also be used to

rearrange a tax imposed on Example 3. It hypothesized: 

“Say that the tax rate on the hypothetical extraction 

tax is 20%. It is true that a 20% tax on 105% of receipts is mathematically equivalent to a 21% tax on 

100% of receipts, the latter of which would satisfy the

gross receipts requirement. PPL proposes that we

make the same move here, increasing the tax rate

from 23% to 51.75% so that there is no multiple of receipts in the tax base. But if the regulation allowed 

us to do that, the example would be a nullity. Any tax 

on a multiple of receipts or profits could satisfy the

gross receipts requirement, because we could reduce 
 

Cite as: 569 U. S. ____ (2013) 13 

Opinion of the Court 

the starting point of its tax base to 100% of gross

receipts by imagining a higher tax rate.” 665 F. 3d, 

at 67. 

The Commissioner reiterates the Third Circuit’s argument. Brief for Respondent 37–38.

There are three basic problems with this approach. As 

the Fifth Circuit correctly recognized, there is a difference 

between imputed and actual receipts. “Example 3 hypothesizes a tax on the extraction of petroleum where the 

income value of the petroleum is deemed to be . . . deliberately greater than actual gross receipts.” Entergy Corp., 

683 F. 3d, at 238. In contrast, the windfall tax depends 

on actual figures. Ibid. (“There was no need to calculate

imputed gross receipts; gross receipts were actually

known”). Example 3 simply addresses a different foreign

taxation issue. 

The argument also incorrectly equates imputed gross 

receipts under Example 3 with net income. See 665 F. 3d, 

at 67 (“[a]ny tax on a multiple of receipts or profits”). As 

noted, a tax is creditable only if it applies to realized gross

receipts reduced by significant costs and expenses attributable to such gross receipts. 26 CFR §1.901–2(b)(4)(i). A 

tax based solely on gross receipts (like the Third Circuit’s 

analysis) would be noncreditable because it would fail the

Treasury Regulation’s net income requirement.

Finally, even if expenses were subtracted from imputed

gross receipts before a tax was imposed, the effect of inflating only gross receipts would be to inflate revenue

while holding expenses (the other component of net income) constant. A tax imposed on inflated income minus

actual expenses is not the same as a tax on net income.5 

—————— 

5Mathematically, the Third Circuit’s hypothetical was incomplete. It 

should have been: 

20% [ 105% (Gross Receipts)−Expenses ] = Tax

But 105% of gross receipts minus expenses is not net income. Thus, the 
 

 

 

14 PPL CORP. v. COMMISSIONER 

Opinion of the Court 

For these reasons, a tax based on imputed gross receipts

is not creditable. But, as the Fifth Circuit explained in 

rejecting the Third Circuit’s analysis, Example 3 is “facially irrelevant” to the analysis of the U. K. windfall tax,

which is based on true net income. Entergy Corp., supra, 

at 238.6 

* * * 

The economic substance of the U. K. windfall tax is that 

of a U. S. income tax. The tax is based on net income, and 

the fact that the Labour government chose to characterize

it as a tax on the difference between two values is not 

dispositive under Treasury Regulation §1.901–2. Therefore, the tax is creditable under §901. 

The judgment of the Third Circuit is reversed. 

It is so ordered. 

—————— 

20% tax is not a tax on net income and is not creditable. 

6An amici brief argues that because two companies had initial periods substantially shorter than four years, the predominant character of 

the U. K. windfall tax was not a tax on income in the U. S. sense. See 

Alstott Brief 29 (discussing Railtrack Group plc and British Energy 

plc). The argument amounts to a claim that two outliers changed the 

predominant character of the U. K. tax. See 135 T. C. 304, 340, n. 33 

(2010) (rejecting this view).

The Commissioner admitted at oral argument that it did not preserve

this argument, a fact reflected in its briefing before this Court and in 

the Third Circuit. See Tr. of Oral Arg. 35–36; Opening Brief for Appellant and Reply Brief for Appellant in No. 11–1069 (CA3). We therefore 

express no view on its merits. 
 

_________________ 

_________________ 

 

 

 

Cite as: 569 U. S. ____ (2013) 1 

SOTOMAYOR, J., concurring 

SUPREME COURT OF THE UNITED STATES 

No. 12–43 

PPL CORPORATION AND SUBSIDIARIES, PETITIONERS v. COMMISSIONER OF INTERNAL REVENUE 

ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF 

APPEALS FOR THE THIRD CIRCUIT 

[May 20, 2013] 

JUSTICE SOTOMAYOR, concurring. 

The Court’s conclusion that the windfall tax is a creditable 

excess profits tax under 26 U. S. C. §901(b)(1) depends on

two interrelated analytic moves: first, restricting the “predominant character” analysis to those companies that shared an

“initial period” of rate regulation of 1,461 days; and second,

treating the tax’s initial period variable as fixed. See ante, 

at 9–10. But there is a different way of looking at this 

case. If the predominant character inquiry is expanded to

include the five companies that had different initial periods, especially those with much shorter

initial periods, it becomes impossible to rewrite the windfall tax as an excess profits tax. Instead, it becomes clear 

that the windfall tax is functionally a tax on value. But 

because the Government took the position at oral argument that the predominant character inquiry should 

disregard such “outlie[r]” companies, see Tr. of Oral Arg. 

38–39, and this argument is therefore only pressed by 

amici, Brief for Anne Alstott et al. as Amici Curiae 28–30 

(hereinafter Alstott Brief), I reserve consideration of this 

argument for another day and another context and join 

the Court’s opinion. 

* * * 

The Internal Revenue Code provides that “income, war 
 

 

2 PPL CORP. v. COMMISSIONER 

SOTOMAYOR, J., concurring 

profits, and excess profits taxes” paid to a foreign country

are creditable. 26 U. S. C. §901(b)(1). Whether a foreign

tax falls within one of these categories depends on whether 

its “predominant character . . . is that of an income tax 

in the U. S. sense.” 26 CFR §1.901–2(a)(1)(ii) (2010). As 

the Court explains, there are three components to this inquiry, ante, at 4–7, but at its core the inquiry simply asks 

whether a foreign tax resembles a typical income, war 

profits, or excess profits tax, ante, at 6. 

Importantly, though, the relevant Treasury Regulations

also provide that a foreign tax “is or is not an income tax,

in its entirety, for all persons subject to the tax.” 26 CFR 

§1.901–2(a)(1). One way to understand this language is

that for a tax to be classed as a creditable income tax, 

its predominant character must be that of an income tax 

with respect to “all persons subject to the tax.” Of course, 

among the many persons subject to a tax, some may face 

tax burdens different from the majority of affected taxpayers. The challenge in applying predominant character 

analysis will sometimes lie in determining whether and 

how such outlier taxpayers affect the characterization of a

given tax.1 

—————— 

1For example, some taxes may produce outliers that might suggest 

that the tax is not an income tax, when in fact the tax is attempting

to reach net gain and therefore has the predominant character of an

income tax. This situation often arises when a tax relies on imperfect 

estimates and assumptions in attempting to calculate net gain. Such a 

tax strives to treat similarly situated taxpayers the same but fails to do

so only because the estimated component inadvertently affects some

taxpayers differently. A situation of this kind occurred in Texasgulf, 

Inc. v. Commissioner, 172 F. 3d 209 (CA2 1999). In that case, a Canadian mining tax did not permit taxpayers to deduct their specific 

expenses, but did permit them to deduct a fixed “processing allowance.” 

Id., at 211–213. The taxpayer argued that the tax was creditable

because the processing allowance was an attempt to reach net income, 

gross income minus expenses, by using “ ‘a method that is likely to

produce an amount that approximates, or is greater than, recovery of

such significant costs and expenditures.’ ” Id., at 215 (quoting 26 CFR 
 

Cite as: 569 U. S. ____ (2013) 3 

SOTOMAYOR, J., concurring 

The windfall tax at issue here exemplifies this problem. 

As the Court notes, ante, at 2–3, the parties stipulated to

the following form of the windfall tax: 

ܦ ൰9× 

ܲ

൨ ܨ ܸ− 36× 5 ൬ × ൤23% = ݔܶܽ

If the predominant character analysis is restricted to those 

27 companies that share an identical initial period length, 

then it makes sense to fix D at 1,461, as the Court does. 

Ante, at 9–10. And from there, it is just a matter of basic 

algebra, ante, at 9, and n. 4, to show that these companies’ 

tax liability is equal to total profits minus a threshold 

amount (in this case, 44.47% of each company’s flotation

value) multiplied by a percentage-form tax rate: ܶܽݔ= 

51.71% × [ܲ − (44.47% × ܸܨ [( See. ante, at 9; Brief for

Petitioners 10. Because an excess profits tax is generally 

a tax levied on the profits of a business beyond a particular threshold, see Wells, Legislative History of Excess 

Profits Taxation in the United States in World Wars I and 

II, 4 Nat. Tax J. 237, 243 (1951), it appears to follow that 

the windfall tax can properly be characterized as an excess 

profits tax. 

But not all of the 32 affected companies had an initial 

—————— 

§1.901–2(b)(4)(i)(B) (1999)). To support its argument, the taxpayer

introduced empirical evidence that roughly 85% of companies facing 

mining tax liability had nonrecoverable expenses less than the processing allowance. Texasgulf, Inc., 172 F. 3d, at 215–216. The Court of 

Appeals agreed with the taxpayer that the tax was a creditable income

tax because it was clear that the mining tax was attempting to reach 

net income, albeit by using an estimate to calculate deductions. Id., 

at 216–217. This result is sensible: A company that happens to have

deductible expenses greater than the fixed amount set by the processing allowance is not an instructive outlier regarding the mining

taxes predominant character. The mining tax is attempting to reach 

that company’s net income, but fails to do only because it relies on an 

approximate value for deductions. 
 

 

4 PPL CORP. v. COMMISSIONER 

SOTOMAYOR, J., concurring 

period length of 1,461 days; 5 of the companies had different initial periods. See App. 34, 39–41. When these 

different initial period values are inserted into the formulation proposed by PPL, two results follow. First, these 

companies have tax rates different from the 51.71% rate 

the Court calculates for the 27 other companies. Second, 

their excess profits threshold also varies. 

For example, consider Railtrack Group, a clear outlier 

with an initial period of 316 days. Inserting this value 

into the stipulated formula yields the following: 

× 9൰ 316

ܲ

൨ ܨ ܸ− 36× 5 ൬ × ൤23% = ݔܶܽ

to the following:

([ ܨܸ × 9.62%)

tively) are very different from those companies with the 

. 

Applying the Court’s algebra, this formula can be reduced 

− ܲ × %] =239.10 ݔܶܽ ܩ݋ݎݏ‘݌ݑ ܽܿ݇ݎݐܴ݈ܽ݅

Railtrack Group’s “effective” tax rate and 

its excess profits threshold (239.10% and 9.62% respeccommon initial period length of 1,461 days (51.71% and 

44.47%). See ante, at 10. Railtrack Group is not alone in 

this respect: four other companies also had tax rates and 

excess profits thresholds that differed from the majority of 

affected companies. See App. 34, 38–40.2 

Once these outlier companies are included in the creditability analysis, it becomes clear that the windfall tax “is 

not an income tax . . . for all persons” subject to it. 26 CFR 

—————— 

2The figures for the other four companies are as follows: Powergen 

plc, which had an initial period of 1,463 days had a tax rate of 51.64%

and an excess profits threshold of 44.54%, App. 38–39; National Power

plc, which had an initial period of 1,456 days, had a rate of 51.89% and 

a threshold of 44.32%, id., at 39–40; Northern Ireland Electricity plc,

which had an initial period of 1,380 days, had a rate of 54.75% and a

threshold of 42.01%, id., at 40; and British Energy plc, which had an

initial period of 260 days, had a rate of 290.60% and a threshold of

7.91%, id., at 34. British Energy, however, did not end up having any 

windfall tax liability. Id., at 33. 
 

 

Cite as: 569 U. S. ____ (2013) 5 

SOTOMAYOR, J., concurring 

§1.901–2(a)(1) (emphasis added). A typical income tax 

applies a fixed percentage rate to a base income that 

varies across taxpayers. An excess profits tax does the 

same, but incorporates a threshold, which may or may not 

vary across taxpayers, to exempt a portion of the base 

from taxation. In contrast, here both of the rate and 

threshold components vary from company to company 

according to the D variable.3 

Seen through this lens, the windfall tax is really a tax 

on average profits. See Alstott Brief 28–30. Under the 

parties’ stipulated form of the windfall tax, each company

pays a fixed tax rate of 23% on a base that is calculated by 

first multiplying a company’s daily average profits during 

ܲ/ܦ

period divided by the length of the initial period) by a fixed 

price-to-earnings ratio; and then subtracting that com-

(ܸܨ)

its initial period (i.e., ( ) , or total profits over the initial 

pany’s flotation value . See ante, at 2. In practice, this

means that, for example, a company that earns $100 

million over 1,461 days would pay approximately the same 

amount of taxes as a company that has earned $25 million

over 365 days. These two companies would have almost 

the same average profits. See Alstott Brief 28. This is not 

how an income tax works. 

The difference between a tax on profits and tax on average profits is especially significant for properly characterizing a tax such as the windfall tax. Average daily profits

multiplied by a price-to-earnings ratio, rather than being a 

—————— 

3At oral argument, PPL contended that an excess profits tax in which 

the excess profits threshold varies according to market capitalization 

would also have an effective tax rate that varies across taxpayers but 

remains creditable. Tr. of Oral Arg. 26–27. That might be true, but 

that does not describe the situation here. In PPL’s hypothetical, any 

shift in the effective tax rate depends on the profits threshold; Here, 

under PPL’s version of the windfall tax, both the effective tax rate and 

the profits threshold move proportionately to a company’s initial period 

length. 
 

 

6 PPL CORP. v. COMMISSIONER 

SOTOMAYOR, J., concurring 

way of approximating income, is a way of approximating 

value.4 See Thompson, A Lawyer’s Guide to Modern Valuation Techniques in Mergers and Acquisitions, 21 J.

Corp. L. 457, 532–533 (1996) (describing similar valuation

techniques using price-to-earnings ratios). Accordingly,

incorporating an outlier like Railtrack Group into the

predominant character analysis suggests that the windfall 

tax is a tax on a company’s value. Railtrack Group and

the companies like it are not random outliers, Brief for 

Petitioners 38, n. 3, but instead are critical pieces of data 

for understanding how the tax actually functioned as a

matter of “economic realit[y].” Commissioner v. Southwest 

Exploration Co., 350 U. S. 308, 315 (1956).

This argument, however, rests on the premise that 

because the relevant regulations state that “a tax either is

or is not an income tax, in its entirety, for all persons 

subject to the tax,” 26 CFR §1.901–2(a)(1)(ii), a tax’s predominant character must be as an income tax for all taxpayers. But if a tax only needs to be an income tax for

“a substantial number of taxpayers” and does not have to

“satisfy the predominant character test in its application 

to all taxpayers,” Exxon Corp. v. Commissioner, 113 T. C. 

338, 352 (1999), then this average profits argument cannot 

get off the ground. Under this reading, the regulations tell 

courts to treat outliers like Railtrack Group as flukes. 

At oral argument, the Government apparently rejected

the notion that “outliers” like Railtrack Group are relevant

to creditability analysis. See Tr. of Oral Arg. 35–39. The 

Government also did not argue these outliers’ relevance 

—————— 

4Petitioners suggested at oral argument that because some of the

outlier taxpayers may have been subject to a more favorable regulatory 

regime in the wake of their privatization, their outsized tax rates are

less meaningful because they could recoup their windfall tax burdens.

See id., at 16–17. Even accepting the premise of this argument, it still

does not change that fact that in “substance,” ante, at 9, the tax functioned as value tax for these companies. 
Cite as: 569 U. S. ____ (2013) 7 

SOTOMAYOR, J., concurring 

before the Court of Appeals, ante, at 14, n. 6, and so this 

argument, and the regulatory interpretation it depends 

upon, has only been presented to this Court by amici, see 

Alstott Brief 17–18, 28–30. We are not barred from considering statutory and regulatory interpretations raised in 

an amicus brief, but we should be “reluctant to do so,” 

Davis v. United States, 512 U. S. 452, 457, n. (1994), when

the issue is one of first impression and the Federal Government has staked out what appears to be a contrary

position. Thus, while I find this argument persuasive, I do

not base my analysis of this case on it and therefore concur in the Court’s opinion.