opinion: ASARCO INC. v. IDAHO STATE TAX COMMISSION
  No. 80-2015.
  Argued April 19, 1982
  Decided June 29, 1982
  Powell, J., delivered the opinion of the Court, in which Burger, C. J., and Brennan, White, Marshall, and Stevens, JJ., joined. Burger, C. J., filed a concurring opinion, post, p. 331. O’Connor, J., filed a dissenting opinion, in which Blackmun and Rehnquist, JJ., joined, post, p. 331.
  George W. Beatty argued the cause for appellant. With him on the briefs were C. Rudolf Peterson, William L. Goldman, James A. Riedy, Philip E. Peterson, and Alexander J. Gillespie, Jr.
  Theodore V. Spangler, Jr., Deputy Attorney General of Idaho, argued the cause for appellee. With him on the brief was David H. Leroy, Attorney General.
  Briefs of amici curiae urging affirmance were filed for the State of Illinois by Tyrone Fahner, Attorney General, Fred H. Montgomery, Special Assistant Attorney General, and Lloyd B. Foster; and for the Multistate Tax Commission et al. by William D. Dexter; Wilson L. Condon, Attorney General of Alaska; J. D. MacFarlane, Attorney General of Colorado; Carl R. Ajello, Attorney General of Connecticut; Richards. Gebelein, Attorney General of Delaware; David H. Leroy, Attorney General of Idaho, and Theodore V. Spangler, Jr., Deputy Attorney General; Linley E. Pearson, Attorney General of Indiana; Robert T. Stephan, Attorney General of Kansas; Stephen H. Sachs, Attorney General of Maryland; Francis X. Bellotti, Attorney General of Massachusetts; Frank K. Kelley, Attorney General of Michigan; Warren R. Spannaus, Attorney General of Minnesota; John Ashcroft, Attorney General of Missouri; Paul L. Douglas, Attorney General of Nebraska; Gregory H. Smith, Attorney General of New Hampshire; Jeff Bingaman, Attorney General of New Mexico; Rufus L. Edmisten, Attorney General of North Carolina, and M. C. Banks, Deputy Attorney General; Robert O. Welfald, Attorney General of North Dakota, and Albert R. Hausauer, Assistant Attorney General; Dave Frohnmayer, Attorney General of Oregon; and David L. Wilkinson, Attorney General of Utah.
  John J. Easton, Attorney General of Vermont, and Paul P. Hanlon filed a brief for the State of Vermont as amicus curiae.
  Justice Powell
  delivered the opinion of the Court.
  The question is whether the State of Idaho constitutionally may include within the taxable income of a nondomiciliary parent corporation doing some business in Idaho a portion of intangible income — such as dividend and interest payments, as well as capital gains from the sale of stock — that the parent receives from subsidiary corporations having no other connection with' the State.
  I
  This case involves corporate income taxes that appellee Idaho State Tax Commission sought to levy on appellant ASARCO Inc. for the years 1968,1969, and 1970. ASARCO is a corporation that mines, smelts, and refines in various States nonferrous metals such as copper, gold, silver, lead, and zinc. It is incorporated in New Jersey and maintains its headquarters and commercial domicile in New York. ASARCO’s primary Idaho business is the operation of a silver mine. It also mines and sells other metals and operates the administrative office of its northwest mining division in Idaho. According to the appellee’s tax calculations, approximately 2.5% of ASARCO’s total business activities take place in Idaho. App. 59a, 67a, and 75a.
  During the years in question, ASARCO received three types of intangible income of relevance to this suit. First, it collected dividends from five corporations in which it owned major interests: M. I. M. Holdings, Ltd.; General Cable Corp.; Revere Copper and Brass, Inc.; ASARCO Mexicana, S. A.; and Southern Peru Copper Corp. Second, ASARCO received interest income from three sources: from Revere’s convertible debentures; from a note received in connection with a prior sale of Mexicana stock; and from a note received in connection with a sale of General Cable Stock. Third, ASARCO realized capital gains from the sale of General Cable and M. I. M. stock.
  In 1965, Idaho adopted its version of the Uniform Division of Income for Tax Purposes Act (UDITPA). See Idaho Code §63-3027 (1976 and Supp. 1981); 7A U. L. A. 91 (1978). Under this statute, Idaho classifies corporate income from intangible property as either “business” or “nonbusiness” income. “Business” income is defined to include income from intangible property when “acquisition, management, or disposition [of the property] constitute^] integral or necessary parts of the taxpayers’ trade or business operations.” Idaho apportions such “business” income according to a three-factor formula and includes this apportioned share of “business” income in the taxpayer’s taxable Idaho income. “Nonbusiness” income, on the other hand, is defined as “all income other than business income.” Idaho Code § 63— 3027(a)(4) (Supp. 1981). Idaho allocates intangible “nonbusiness” income entirely to the State of the corporation’s commercial domicile instead of apportioning it among the States in which a corporate taxpayer owns property or carries on business.
  Idaho is a member of the Multistate Tax Compact, an interstate taxation agreement concerning state taxation of multistate businesses. The Compact established the Multistate Tax Commission, which is composed of the tax administrators from the member States. Article VIII of the Compact provides that any member State may request that the Commission perform an audit on its behalf. See United States Steel Corp. v. Multistate Tax Comm’n, 434 U. S. 452, 457 (1978) (upholding the Compact against a facial attack on Compact and Commerce Clauses and Fourteenth Amendment grounds).
  In 1971, the Multistate Tax Commission audited ASARCO’s tax returns for the years in question on behalf of six States, including Idaho. The auditor recommended adjusting ASARCO’s tax computations in several respects. As accepted by the Idaho State Tax Commission and as relevant to the present dispute, the auditor first “unitized” — or treated as one single corporation — ASARCO and six of its wholly owned subsidiaries. As a consequence of unitization, the auditor combined ASARCO’s income with that of these six subsidiaries and disregarded (as intracompany accounting transfers) the subsidiaries’ dividend payments to ASARCO. Cf. United States Steel Corp. v. Multistate Tax Comm'n, supra, at 473, n. 25. The auditor listed five factors thought to justify unitizing treatment. First, ASARCO owned a majority (in fact, all) of the stock of each subsidiary. Second, “ASARCO, with its subsidiaries, conducts a vertically integrated non-ferrous metals operation. This is evidenced by the flow from the mines to the smelters to the refineries and ultimately to the sales made by the New York office.” App. 88a. Third, “ASARCO and its subsidiaries have interlocking officers and directors, which enables ASARCO to control the major management decisions of each subsidiary.” Ibid. Fourth, sales between the companies were numerous, making it “apparent. . . that the companies supplied markets to each other . . . .” Id., at 89a. And finally, various services were provided to the ASARCO group either by ASARCO or by subsidiaries specifically set up for such a purpose. The propriety of this treatment of the six wholly owned subsidiaries is not an issue before us.
  The auditor found the situation to differ with respect to ASARCO’s interest in M. I. M., General Cable, Revere, Mexicana, and Southern Peru. This judgment planted the seed of the current dispute. As to these five companies, the auditor determined that the links with ASARCO were not sufficient to justify unitary treatment. Nonetheless, he found that ASARCO’s receipt of dividends from each of these did constitute “business” income to ASARCO. See n. 4, supra. The auditor similarly classified the interest and capital gains income at issue in this case. These categories of income also were added in ASARCO’s total income to be apportioned among the various States in which ASARCO was subjected to an income tax.
  The Idaho State Tax Commission adopted the auditor’s adjustments in an unreported decision. App. to Juris. Statement 46a. In rejecting ASARCO’s challenge to the auditor’s unitized treatment of the six wholly owned corporations, see n. 8, supra, the Commission stated that it was “quite clear from the evidence produced at the hearing that [ASARCO’s] business activities are so inter-related as to defy measurement by separate accounting . . . .” App. to Juris. Statement 49a-50a. The Commission likewise upheld the auditor’s conclusion that the dividends presently at issue were properly treated as apportionable “business” income. It consequently assessed tax deficiencies against ASARCO of $92,471.88 for 1968, $111,292.44 for 1969, and $121,750.76 for 1970, plus interest.
  On ASARCO’s petition for review, the State District Court upheld the Commission's unitized treatment of the six subsidiaries in an unpublished opinion. The court, however, overruled the Commission’s determination that the disputed dividends, interest, and capital gains constituted “business” income, on the reasoning that this income did not come from property or activities that were “an integral part of [ASARCO’s] trade or business.” Idaho Code § 63-3027(a)(l) (Supp. 1981). In the court’s view, “if the dividend income from other corporations is an integral part of the business of [ASARCO] . . . they should be unitized and all matters considered and[,] if they are not[,] . . . the income is not business income but is [nonapportionable] non business income.” App. to Juris. Statement 37a.
  The Commission, but not ASARCO, appealed to the Idaho Supreme Court. That court held that the trial court had erred by excluding from “business” income ASARCO’s receipt of dividends, interest, and capital gains as a result of its owning stock in the five corporations. American Smelting & Refining Co. v. Idaho State Tax Comm’n, 99 Idaho 924, 935-937, 592 P. 2d 39, 50-52 (1979). In response to ASARCO’s constitutional arguments, the court decided that this tax treatment withstood attack under the Commerce and Due Process Clauses. We vacated and remanded the case for reconsideration in light of our decision in Mobil Oil Corp. v. Commissioner of Taxes of Vermont, 445 U. S. 425 (1980). ASARCO Inc. v. Idaho State Tax Comm’n, 445 U. S. 939 (1980). The Idaho Supreme Court reinstated its previous opinion in a brief per curiam order on March 4, 1981. 102 Idaho 38, 624 P. 2d 946. We noted probable jurisdiction, 454 U. S. 812 (1981), and we now reverse.
  II
  As a general principle, a State may not tax value earned outside its borders. See, e. g., Connecticut General Life Ins. Co. v. Johnson, 303 U. S. 77, 80-81 (1938). The broad inquiry in a case such as this, therefore, is “whether the taxing power exerted by the state bears fiscal relation to protection, opportunities and benefits given by the state. The simple but controlling question is whether the state has given anything for which it can ask return.” Wisconsin v. J. C. Penney Co., 311 U. S. 435, 444 (1940).
  Our application of this general principle in this case is guided by two of our recent decisions. In Mobil Oil Corp. v. Commissioner of Taxes of Vermont, supra, the taxpayer conducted “an integrated petroleum business,” 445 U. S., at 428, that included international petroleum exploration, production, refining, transportation, distribution, and sale of petroleum, as well as related chemical and mining enterprises. Much of its business abroad was conducted through wholly or partly owned subsidiaries. The State of Vermont imposed a corporate income tax on that portion of Mobil’s total income that the State attributed to Mobil’s Vermont activity, which was confined to the wholesale and retail marketing of petroleum. The State sought to include within Mobil’s apportion-able Vermont income its receipt of dividends from its subsidiaries and affiliates that operated abroad. Mobil protested that the State could not properly apportion and tax this “foreign source” dividend income.
  For present purposes, our analysis in Mobil began with the observation that Mobil’s principal dividend payors were part of Mobil’s integrated petroleum business. Although Mobil was “unwilling to concede the legal conclusion” that activities by these dividend payors formed part of Mobil’s “‘unitary business,’ ” it “offered no evidence that would undermine the conclusion that most, if not all, of its subsidiaries and affiliates contribute^] to [Mobil’s] worldwide petroleum enterprise.” Id., at 435.
  The Court next stated that due process limitations on Vermont’s attempted tax would be satisfied if there were “a ‘minimal connection’ between the interstate activities and the taxing State, and a rational relationship between the income attributed to the State and the intrastate values of the enterprise.” Id., at 436-437, citing Moorman Mfg. Co. v. Bair, 437 U. S. 267, 272-273 (1978); National Bellas Hess, Inc. v. Illinois Dept. of Revenue, 386 U. S. 753, 756 (1967); Norfolk & Western R. Co. v. Missouri Tax Comm’n, 390 U. S. 317, 325 (1968). And we said that these limitations would not be contravened by state apportionment and taxation of income that were determined by geographic accounting to have arisen from a different State “so long as the intrastate and extrastate activities formed part of a single unitary business.” 445 U. S., at 438 (emphasis added).
  The Mobil Court explicated the limiting “unitary business” principle by observing, that geographic accounting, in purporting to isolate income received in various States, “may fail to account for contributions to income resulting from functional integration, centralization of management, and economies of scale.” Ibid. The fact that “these factors of profitability arise from the operation of the business as a whole,” ibid., therefore could justify a State’s otherwise impermissible inclusion of corporate income derived from corporate activities beyond the State’s borders. The Court thus stated:
  “[T]he linchpin of apportionability in the field of state income taxation is the unitary-business principle. In accord with this principle, what appellant must show, in order to establish that its dividend income is not subject to an apportioned tax in Vermont, is that the income was earned in the course of activities unrelated to the sale of petroleum products in that State. [Mobil] has made no effort to demonstrate that the foreign operations of its subsidiaries and affiliates are distinct in any business or economic sense from its petroleum sales activities in Vermont. Indeed, all indications in the record are to the contrary, since it appears that these foreign activities are part of [Mobil’s] integrated petroleum enterprise. In the absence of any proof of discrete business enterprise, Vermont was entitled to conclude that the dividend income’s foreign source did not destroy the requisite nexus with in-state activities.” Id., at 439-440 (emphasis added and footnote omitted).
  We consequently rejected Mobil’s constitutional challenge to Vermont’s tax. In so doing, however, we cautioned that we did
  “not mean to suggest that all dividend income received by corporations operating in interstate commerce is necessarily taxable in each State where that corporation does business. Where the business activities of the dividend payor have nothing to do with the activities of the recipient in the taxing State, due process considerations might well preclude apportionability, because there would be no underlying unitary business.” Id., at 441-442 (emphasis added).
  We soon had occasion to reiterate these principles. Three months after Mobil, we decided Exxon Corp. v. Wisconsin Dept. of Revenue, 447 U. S. 207 (1980). In Exxon, “a vertically integrated petroleum company,” id., at 210, explored for, produced, refined, and marketed petroleum and related products. Although Exxon’s activities in Wisconsin were confined to marketing, the State sought to apportion and tax Exxon’s income from nonmarketing activities in the United States.
  Exxon disputed the propriety of this treatment. The Wisconsin Tax Appeals Commission agreed with the objection on the basis of its conclusion that Exxon’s “three main functional operating departments — Exploration and Production, Refining, and Marketing — were separate unitary businesses.” Id., at 215 (emphasis added). The Commission found that the tax as applied “ ‘had the effect of imposing a tax on [Exxon’s] exploration and on its refining net income, all of which was derived solely from operations outside the State of Wisconsin and which had no integral relationship to [Exxon’s] marketing operations within Wisconsin.’” Ibid. On appeal, however, the Circuit Court for Dane County held that Exxon’s three main functional operating departments were all part of a single unitary business. The Wisconsin Supreme Court agreed.
  In reviewing the case, this Court unanimously agreed with the State Commission and the two state courts that the decisive concept in the case was that of a unitary business. Significantly, we repeated Mobil’s teaching that “[t]he ‘linchpin of apportionability’ for state income taxation of an interstate enterprise is the ‘unitary-business principle.’” Id., at 223, quoting Mobil, 445 U. S., at 439. We also repeated:
  “In order to exclude certain income from the apportionment formula, the company must prove that ‘the income was earned in the course of activities unrelated to the sale of petroleum products in that State.’. . . The court looks to the ‘underlying economic realities of a unitary business,’ and the income must derive from ‘unrelated business activity’ which constitutes a ‘discrete business enterprise,’ 445 U. S., at 441, 442, 439.” 447 U. S., at 223-224.
  Examining the facts, the Court found that Exxon was “a highly integrated business which benefits from an umbrella of centralized management and controlled interaction.” Id., at 224. We rejected the company’s protest because “[w]e agree[d] with the Wisconsin Supreme Court that Exxon [was] such a unitary business and that Exxon has not carried its burden of showing that its functional departments are ‘discrete business enterprises’. . . .” Ibid,.
  Ill
  In this case, ASARCO claims that it has succeeded, where the taxpayers in Mobil and Exxon failed, in proving that the dividend payors at issue are not part of its unitary business, but rather are “discrete business enterprises.” 447 U. S., at 224. We must test this contention on the record before us.
  A
  The closest question is posed by ASARCO’s receipt of dividends from Southern Peru. ASARCO is one of Southern Peru’s four shareholders, holding 51.5% of its stock. Southern Peru produces smelted but unrefined “blister copper” in Peru, and sells 20-30% of its output to the Southern Peru Copper Sales Corp. The remainder of Southern Peru’s output is sold under contracts to its shareholders in proportion to their ownership interests. Southern Peru sold about 35% of its output to ASARCO, App. 89a, at prices determined by reference to average representative trade prices quoted in a trade publication and over which the parties had no control. Id., at 125a-126a; 99 Idaho, at 928, 592 P. 2d, at 43.
  ASARCO’s majority interest, if asserted, could enable it to control the management of Southern Peru. The Idaho State Tax Commission, however, found that Southern Peru’s “remaining three shareholders, owning the remainder of the stock, refuse[d] to participate in [Southern Peru] unless assured that they would have a way to assure that management would not be completely dominated by ASARCO.” App. to Juris. Statement 55. Consequently ASARCO entered a management agreement giving it the right to appoint 6 of Southern Peru’s 13 directors. The other three shareholders also appointed six directors. Ibid. The thirteenth and final director is appointed by the joint action of either the shareholders or the first 12 directors. Ibid.; App. 121a. Southern Peru’s bylaws provide that eight votes are required to pass any resolution, ibid, and its articles and bylaws can be changed only by unanimous consent of the four stockholders.
  In its unreported opinion, the state trial court concluded that this management contract “insures that [ASARCO] will not be able to control [Southern Peru].” App. to Juris. Statement 43a. It likewise found that Southern Peru “operates independently of [ASARCO].” Id., at 42a. The court reached this conclusion after hearing testimony that ASARCO did not “control Southern Peru in any sense of that term,” App. 121a, and that Southern Peru did not “seek direction or approval from ASARCO on major decisions.” Id., at 124a. Idaho does not dispute any of these facts. In view of the findings and the undisputed facts, we conclude that ASARCO’s Idaho silver mining and Southern Peru’s autonomous business are insufficiently connected to permit the two companies to be classified as a unitary business.
  B
  Under the principles of our decisions, the relationship of each of the other four subsidiaries to ASARCO falls far short of bringing any of them within its unitary business. M. I. M. Holdings engages in the mining, milling, smelting, and refining of copper, lead, zinc, and silver in Australia. The company also operates a lead and zinc refinery in England. During the years in question M. I. M. sold only about 1% of its output to ASARCO, for sums in the range of $0.2 to $2.2 million. Id., at 43a-47a. It appears that these sales were on the open market at prevailing market rates. ASARCO owns 52.7% of M. I. M.’s stock, and the rest is widely held. Although ASARCO has the control potential to manage M. I. M., no claim is made that it has done so. As an ASARCO executive explained, it never even elected a member of M. I. M.’s board:
  “This company has been very successful in staffing the corporation with Australian people and [they have] been able to run this company by themselves and, therefore, in consequence of the nationalistic feeling which develops in most of such developing countries we have not exercised any right we might have to elect a director to the board of the company.” Id., at 132a.
  In addition to forgoing its right to elect directors, ASARCO similarly has taken no part in the selection of M. I. M.’s officers — a function of the board of directors. Nor do the two companies have any common directors or officers. Id., at 34a, 40a. The state trial court found that M. I. M. “operates entirely independently of and has minimal contact with” ASARCO. App. to Juris. Statement 43a. As the business relation also is nominal, it is clear that M. I. M. is merely an investment. See, e. g., Keesling & Warren, The Unitary Concept in the Allocation of Income, 12 Hastings L. J. 42, 52-53 (1960).
  General Cable and Revere Copper, large publicly owned companies, fabricate metal products. Both are ASARCO customers. But ASARCO held only minority interests, owning approximately 34% of the outstanding common shares of each. The remaining shares — listed on the New York Stock Exchange — are widely held. App. 135a. The two companies occupy parallel positions with respect to ASARCO as a result of a 1961 Department of Justice antitrust suit against ASARCO. The suit was based on ASARCO’s interests in each. In 1967, ASARCO consented to a decree that prohibited it from maintaining common officers in these companies, voting its stock in them, selling the companies copper at prices below those quoted to their competition, and from acquiring stock in any other copper fabricator. Id., at 96a. Neither Revere’s nor General Cable’s management seeks direction or approval from ASARCO on operational or other management decisions. Id., at 137a.
  Mexicana mines and smelts lead and copper in Mexico. Originally it was a wholly owned subsidiary of ASARCO, but a change in Mexican law required ASARCO to divest itself of 51% of Mexicana’s stock in 1965. This stock is now publicly held by Mexican nationals. The record does not reveal whether ASARCO and Mexicana have any common directors. The state trial court found, however, that Mexicana “operates independently of [ASARCO],” App. to Juris. Statement 43a, and the Idaho Supreme Court stated that “Mexicana does not seek approval from ASARCO concerning major policy decisions . . . .” 99 Idaho, at 929, 592 P. 2d, at 44.
  c
  Idaho does not dispute the foregoing facts. Neither does it question that a unitary business relationship between ASARCO and these subsidiaries is a necessary prerequisite to its taxation of the dividends at issue. E. g., Brief for Appellee 10 (“When income is earned from activities which are part of a unitary business conducted in several states, then the requirement that the income bear relation to the benefits and privileges conferred by the several states has been met”). See also Tr. of Oral Arg. 25 (“[W]hen intangible assets such as, for example, shares of stock, are found to be a part of a taxpayer’s own unitary business,. . . there is no logical or constitutional reason why the income from those same intangibles should be treated any differently than any other business income that that taxpayer might earn”). Rather the State urges that we expand the concept of a “unitary business” to cover the facts of this case.
  Idaho’s proposal is that corporate purpose should define unitary business. It argues that intangible income should be considered a part of a unitary business if the intangible property (the shares of stock) is “acquired, managed or disposed of for purposes relating or contributing to the taxpayer’s business.” Brief for Appellee 4. See also Tr. of Oral Arg. 25 (urging that income from intangible property be considered part of a unitary business when the intangibles “contribute to or relate to or are some way in furtherance of the taxpayer’s own trade or business”). Idaho asserts that “[i]t is this integration — i. e., between the business use of the intangible asset (the shares of stock) and ASARCO’s mining, smelting, and refining business — which makes the income part of the unitary business.” Brief for Appellee 4.
  This definition of unitary business would destroy the concept. The business of a corporation requires that it earn money to continue operations and to provide a return on its invested capital. Consequently all of its operations, including any investment made, in some sense can be said to be “for purposes related to or contributing to the [corporation’s] business.” When pressed to its logical limit, this conception of the “unitary business” limitation becomes no limitation at all. When less ambitious interpretations are employed, the result is simply arbitrary.
  We cannot accept, consistently with recognized due process standards, a definition of “unitary business” that would permit nondomiciliary States to apportion and tax dividends “[w]here the business activities of the dividend payor have nothing to do with the activities of the recipient in the taxing State . . . .” Mobil Oil Corp. v. Commissioner of Taxes of Vermont, 445 U. S., at 442. In such a situation, it is not true that “the state has given anything for which it can ask return.” Wisconsin v. J. C. Penney Co., 311 U. S., at 444.
  Justice Holmes stated long ago that “the possession of bonds secured by mortgages of lands in other States, or of a land-grant in another State or of other property that adds to the riches of the corporation but does not affect the [taxing State’s] part of the [business] is no sufficient ground for the increase of the tax — whatever it may be . . . .” Wallace v. Hines, 253 U. S. 66, 69-70 (1920). In this case, it is plain that the five dividend-paying subsidiaries “add to the riches” of ASARCO. But it is also true that they are “discrete business enterprise[s]” that — in “any business or economic sense” — have “nothing to do with the activities” of ASARCO in Idaho. Mobil, supra, at 439-442. Therefore there is no “rational relationship between the [ASARCO dividend] income attributed to the State and the intrastate values of the enterprise. Moorman Mfg. Co. v. Bair, 437 U. S. 267, 272-273 (1978).” Mobil, supra, at 437. Idaho’s attempt to tax a portion of these dividends can be viewed as “a mere effort to reach profits earned elsewhere under the guise of legitimate taxation.” Bass, Ratcliff & Gretton, Ltd. v. State Tax Comm’n, 266 U. S. 271, 283 (1924). The Due Process Clause bars such an effort to levy upon income that is not properly “within the reach of [Idaho’s] taxing power.” Connecticut General Life Ins. Co. v. Johnson, 303 U. S., at 80.
  IV
  In addition to the disputed dividend income, Idaho also has sought to tax certain ASARCO interest and capital gains income. The interest income arose from a note ASARCO received from its sale of Mexicana stock and from a Revere convertible debenture, as well as in connection with ASARCO’s 1970 disposition of its General Cable stock. See n. 21, supra. The General Cable stock sale also generated capital gains for ASARCO, as did ASARCO’s sale of a portion of its stock in M. I. M.
  Idaho and ASARCO agree that interest and capital gains income derived from these companies should be treated in the same manner as the dividend income. Brief for Appellant 27; Brief for Appellee 21. Cf. 99 Idaho, at 937, 592 P. 2d, at 52 (“In our view the same standard applies to the question whether gains from the sale of stock are business income as applies to the question whether dividends from the stock are business income”). We also agree. “One must look principally at the underlying activity, not at the form of investment, to determine the propriety of apportionability.” Mobil, 445 U. S., at 440. Changing the form of the income “works no change in the underlying economic realities of [whether] a unitary business [exists], and accordingly it ought not to affect the apportionability of income the parent receives.” Id., at 441. We therefore hold that Idaho’s attempt to tax this income also violated the Due Process Clause.
  V
  For the reasons stated, the judgment of the Supreme Court of Idaho is
  Reversed.
  ASARCO also received other intangible income, but the proper tax treatment of that income is not at issue in this case.
  M. I. M. Holdings, Ltd., is a publicly owned corporation engaged in the mining, milling, smelting, and refining of nonferrous metals in Australia and England. ASARCO owned about 53% of M. I. M.’s stock during the period in question. General Cable Corp. and Revere Copper and Brass, Inc., are publicly owned companies that respectively fabricate cables and manufacture copper wares. ASARCO owned about 34% of the stock of each. ASARCO Mexicana, S. A., engages in Mexico in the same general line of business as does ASARCO in the United States. ASARCO owned 49% of Mexicana. Southern Peru Copper Corp. mines and smelts copper in Peru. ASARCO owned about 51.5% of Southern Peru during the time at issue.
  The UDITPA is a tax allocation system approved in 1957 by the National Conference of Commissioners on Uniform State Laws and by the American Bar Association. See 7A U. L. A. 91 (1978). At least 23 States have adopted substantially all of the UDITPA to date. See id., at 10 (Supp. 1982); Brief for State of Illinois as Amicus Curiae 1-2. The UDITPA has been adopted as Article IV of the Multistate Tax Compact. See United States Steel Corp. v. Multistate Tax Comm’n, 434 U. S. 452, 457-458, n. 6 (1978).
  Idaho Code § 63-3027(a)(l) (Supp. 1981). The complete definition provides that “ ‘[b]usiness income’ means income arising from transactions and activity in the regular course of the taxpayers’ trade or business and includes income from the acquisition, management, or disposition of tangible and intangible property when such acquisition, management, or disposition constitute[s] integral or necessary parts of the taxpayers’ trade or business operations. Gains or losses and dividend and interest income from stock and securities of any foreign or domestic corporation shall be presumed to be income from intangible property, the acquisition, management, or disposition of which constitute an integral part of the taxpayers’ trade or business; such presumption may only be overcome by clear and convincing evidence to the contrary.” Ibid, (emphasis added). See UDITPA, § 1(a), 7A U. L. A. 93 (1978).
  “All business income shall be apportioned to this state by multiplying the income by a fraction, the numerator of which is the property factor plus the payroll factor plus the sales factor, and the denominator of which is three (3).” Idaho Code § 63-3027(i) (Supp. 1981).
  “The property factor is a fraction, the numerator of which is the average value of the taxpayer’s real and tangible personal property owned or rented and used in this state during the tax period and the denominator of which is the average value of all the taxpayer’s real and tangible personal property owned or rented and used during the tax period.” § 63 — 3027(j). “The payroll factor is a fraction, the numerator of which is the total amount paid in this state during the tax period by the taxpayer for compensation, and the denominator of which is the total compensation paid everywhere during the tax period.” § 63-3027(m). “The sales factor is a fraction, the numerator of which is the total sales of the taxpayer in this state during the tax period, and the denominator of which is the total sales of the taxpayer everywhere during the tax period.” § 63-3027(o).
  “Capital gains and losses from sales of intangible personal property are allocable to this state if the taxpayer’s commercial domicile is in this state, unless such gains and losses constitute business income as defined in this section.” Idaho Code § 63 — 3027(f)(3) (Supp. 1981). “Interest and dividends are allocable to this state if the taxpayer’s commercial domicile is in this state unless such interest or dividends constitute business income as defined in this section.” § 63-3027(g).
  Idaho defines “commercial domicile” as “the principal place from which the trade or business of the taxpayer is directed or managed.” § 63-3027(a) (2).
  Presently 19 States and the District of Columbia have joined the Compact as full members. Eleven States have joined as associate members. Brief for Multistate Tax Commission and Participating States as Amici Curiae 2.
  Idaho law provides that “two ... or more corporations the voting stock of which is more than fifty percent. . . owned directly or indirectly by a common owner or owners may, when necessary to accurately reflect income, be considered a single corporation.” Idaho Code §63-3027(s) (Supp. 1981).
  The six unitized subsidiaries are Federated Metals of Canada; ASARCO Mercantile Co.; Enthone, Inc.; International Mining Co.; Lone Star Lead Construction Corp.; and Northern Peru Mining Corp.
  The auditor also stated that Southern Peru Copper Corp. and Southern Peru Copper Sales Corp. “were deemed unitary and were combined only for those states in which ownership of less than 80% presents no problem.” App. 88a. See Mobil Oil Corp. v. Commissioner of Taxes of Vermont, 445 U. S. 425, 435, n. 12 (1980). These two corporations were not “deemed unitary” in Idaho.
  The auditor noted that ASARCO Mercantile bought and sold equipment for the subsidiaries and that International Metals acted as ASARCO’s foreign sales agent. He further observed that exploration, research and development, insurance procurement, and tax preparation were performed jointly for most or all of these companies. Finally, he stated that ASARCO’s audit staff examined the operations of these subsidiaries to enable “ASARCO to know whether the subsidiaries are operating along the lines set down by its management.” App. 90.
  The Idaho Supreme Court also ruled that ASARCO’s receipt of certain rents and royalties, as well as its receipt of dividends from Compañía American Smelting, S. A., constituted apportionable “business” income. It further upheld the trial court’s “nonbusiness” income classification with respect to dividends received by ASARCO from Lake Asbestos of Quebec, ASARCO International Corp., Hecla Mining Co., Kennecott Copper Co., Phelps-Dodge, and United Park City Mines. American Smelting & Refining Co. v. Idaho State Tax Comm’n, 99 Idaho 924, 935-937, 592 P. 2d 39, 50-52 (1979).
  These rulings are not disputed here.
  See Rudolph, State Taxation of Interstate Business: The Unitary Business Concept and Affiliated Corporate Groups, 25 Tax L. Rev. 171, 181 (1970).
  That court examined Exxon’s organizational structure and business operations. It found that Exxon’s full utilization of its production and refining functions were dependent on its marketing system, which encompassed Exxon’s Wisconsin activities. The court therefore agreed with the Circuit Court for Dane County that Exxon’s marketing in Wisconsin was an integral part of one unitary business and, consequently, that its total corporate income derived from the United States was subject to Wisconsin’s apportioned taxation. See 447 U. S., at 217-219.
  It was noted that Exxon’s Coordination and Services Management office “provided many essential corporate services for the entire company, including the coordination of the refining and other operational functions ‘to obtain an optimum short range operating program.’ . . . Many of the items sold by appellant in Wisconsin were obtained through a centralized purchasing office in Houston whose obvious purpose was to increase overall corporate profits through bulk purchases and efficient allocation of supplies among retailers. . . . Even the gasoline sold in Wisconsin was available only because of an exchange agreement with another company arranged by the Supply Department, part of Coordination and Services Management, and the Refining Department. Similarly, sales were facilitated through the use of a uniform credit card system, uniform packaging, brand names, and promotional displays, all run from the national headquarters.” Id., at 224.
  The unitary-business principle applied in Mobil and Exxon is not new. It has been a familiar concept in our tax cases for over 60 years. See United States Steel Corp. v. Multistate Tax Comm’n, 434 U. S., at 473, n. 25, 474, n. 26; General Motors Corp. v. Washington, 377 U. S. 436, 439 (1964); Northwestern States Portland Cement Co. v. Minnesota, 358 U. S. 450, 460 (1959); Butler Bros. v. McColgan, 315 U. S. 501, 508 (1942); Ford Motor Co. v. Beauchamp, 308 U. S. 331, 336 (1939); Norfolk & Western R. Co. v. North Carolina ex rel. Maxwell, 297 U. S. 682, 684 (1936); Hans Rees’ Sons, Inc. v. North Carolina ex rel. Maxwell, 283 U. S. 123, 132-133 (1931); Bass, Ratcliff & Gretton, Ltd. v. State Tax Comm’n, 266 U. S. 271, 282 (1924). Cf. Burnet v. Aluminum Goods Mfg. Co., 287 U. S. 544, 550 (1933); Underwood Typewriter Co. v. Chamberlain, 254 U. S. 113, 120-121 (1920); Wallace v. Hines, 253 U. S. 66, 69 (1920); Fargo v. Hart, 193 U. S. 490, 499-500 (1904); Adams Express Co. v. Ohio State Auditor, 165 U. S. 194, 221-222 (1897); Adams Express Co. v. Ohio State Auditor, 166 U. S. 185, 219, 222, 223-224 (1897).
  A review of our cases before Mobil made plain that “[f]ormulary apportionment, which takes into account the entire business income of a multistate business in determining the income taxable by a particular state, is constitutionally permissible only in the case of a unitary business.” Rudolph, supra n. 11, at 183-184.
  The other shareholders are Phelps Dodge, 16%; Newmont Mining, 10.25%; and Cerro Corp., 22.25%. App. 86a. Either these large companies or their parents were traded on the New York Stock Exchange at the time in question.
  Southern Peru Copper Sales Corp. in turn sells the copper to European customers. These European sales are handled in this manner to preserve Southern Peru’s favorable federal tax status as a Western Hemisphere Trading Corporation.
  Southern Peru Copper Sales Corp.’s stock is owned in the same manner as is Southern Peru’s. Unlike Southern Peru, however, Southern Peru Copper Sales Corp. has no employees of its own. Sales are generally transacted by ASARCO’s New York office, for which that office earns a sales commission. Ibid.
  These sales ranged between $44 and $65 million for the years in question. Id., at 89a. There was evidence that ASARCO could replace this output contract “[wlithin a short time” if it were lost, and that loss of ASARCO’s ownership in Southern Peru would not cause the loss of the output contract. Id., at 128a.
  Southern Peru has a “staff that you’d expect a major corporation to have.” Id., at 122a. ASARCO provided Southern Peru with purchasing service outside of Peru, traffic service for its exports and imports outside of Peru, and preparation service for its United States tax return. Id., at 123a-124a. The contract for ASARCO’s purchasing services provided for payment of this service on the basis of a fixed fee plus a commission based on the dollar volume of purchases. Id., at 124a. ASARCO received separate “negotiated fair fee[s]” for its tax and traffic services. Ibid. Southern Peru has its own purchasing, traffic, and tax departments in Peru. Id., at 123a.
  M. I. M. did use an ASARCO melting furnace patent for which it pays a price “the same that would be paid by any other company using it.” Id., at 133a.
  For the years in question, Revere’s purchases averaged 3-4% of ASARCO’s sales and totalled from $17 to $29 million. Id., at 27a. Revere in turn sold ASARCO from 1 to 2% of its total output, which totalled $4-$6 million. Id., at 43a-47a. General Cable’s purchases accounted for approximately 6% of ASARCO’s sales and ranged from $31 to $47 million. Id., at 27a. ASARCO’s purchases from General Cable averaged 0.1% of General Cable’s total sales and ranged between $0.3 and $0.5 million. Id., at 43a-47a.
  Both Revere and General Cable utilized ASARCO’s stock transfer department on a contract basis, and Revere licensed one patent from ASARCO for a “fair price.” Id., at 136a.
  In 1970, ASARCO was compelled, apparently by the Department of Justice, to divest itself of all its General Cable stock. Id., at 95a.
  ASARCO sold Mexicana none of its output in 1968 and insignificant amounts (totalling $24,169 and $14,902) in 1969 and 1970. Id., at 27a. Mexicana apparently did not sell ASARCO any of its output during the time in question. Id., at 43a-47a. For a commission, ASARCO does act as a contract sales agent for Mexicana in the United States. Id., at 131a. This contract would continue if ASARCO lost its investment interest in Mexicana. Ibid. ASARCO also provides technical services to Mexicana for a fee. Id., at 130a; 99 Idaho, at 929, 592 P. 2d, at 44.
  The dissent’s perception of some of the facts differs substantially from the record. It speculates that ASARCO’s unitary-business experience “must” have aided ASARCO’s stock investments, post, at 336, despite the undisputed trial court finding that ASARCO’s stock investments were “not integral to nor a necessary part of [ASARCO’s] business operation . . . .” App. to Juris. Statement 44a. See also id., at 43a. It maintains that— “[f]or all we know” — ASARCO’s stock investments were interim uses of idle funds “accumulated for the future operation of [ASARCO’s] own primary business.” Post, at 337. The trial court, however, found that ASARCO “has never been required to utilize its stock as security for borrowing of working capital, acquiring stock or securities in other companies or to support any bond issues.” App. to Juris. Statement 41a. Moreover, ASARCO was found to have “sufficient cash flow from mining to provide operating capital for all mining operations without reliance upon cash flow from . . . income from intangibles.” Ibid.
  The dissent also describes the five companies as “captive suppliers and customers. . . .” Post, at 342. This description is at odds with the undisputed facts. See supra, at 320-324.
  Cf. Keesling & Warren, California’s Uniform Division of Income for Tax Purposes Act, Part I, 15 UCLA L. Rev. 156, 172 (1967).
  Such arbitrariness is evident in this case. As previously noted, see n. 10, supra, ASARCO received dividend income from Lake Asbestos of Quebec. Lake Asbestos is a wholly owned subsidiary of ASARCO that is engaged in extracting and processing asbestos fibers in Canada. App. 86a. Its selling agent is ASARCO International, another wholly owned ASARCO subsidiary. Ibid. The Idaho Supreme Court found that “Lake Asbestos has its own staff, but ASARCO provides important management services. Lake Asbestos seeks ASARCO’s direction and approval on major policy decisions.” 99 Idaho, at 929, 592 P. 2d, at 44.
  Lake Asbestos consequently appears in many respects to be more likely to qualify as part of ASARCO’s unitary business than does any of the five corporations involved in this case. Yet Idaho now agrees, as the courts below held, that on this record Lake Asbestos is not part of such a business. See Tr. of Oral Arg. 39.
  ASARCO also received approximately $250,000 a year in dividends from Kennecott Copper Corp., and approximately $300,000 a year in dividends from Phelps Dodge. App. 52a. The record describes the business of these two corporations as the mining, smelting, refining, and sale of copper. Id., at 50a. ASARCO made sales in the range of $3-$5 million a year to Kennecott, and $24,000-$800,000 a year to Phelps Dodge. Id., at 27a. Each in turn made some (albeit “minimal”) sales to ASARCO. Id., at 43a-47a.
  In light of this information, we have no basis for concluding that ASARCO did not “acquire” stock in Kennecott and Phelps Dodge “for purposes relating or contributing to the taxpayer’s business.” Brief for Appellee 4. ASARCO’s management scarcely would make such an admission. Yet Idaho makes no claim that Kennecott and Phelps Dodge are part of ASARCO’s unitary business.
  Justice O’Connor’s dissent views the Court’s decision as “prohibiting apportioned taxation of investment income by nondomiciliary states.” Post, at 345 et seq. This reflects a serious misunderstanding of our decision today and the eases on which we rely. The case we follow primarily is Mobil. It sustained the taxation of investment income after applying enunciated principles carefully to the facts of the case. In this case we have applied the same principles but have reached a different result because the facts differ in critical respects. As we have said elsewhere, the application of the unitary-business principle requires in each case a careful examination both of the way in which the corporate enterprise is structured and operates, and of the relationship with the taxing State.
  The dissent, argues that our reliance on the Due Process Clause is inappropriate. It also says that our holding that Idaho has exceeded its jurisdiction to tax somehow “strip[s] Congress of the authority” to authorize or regulate state taxation. Post, at 331. See also post, at 349-350, 353. In analyzing the validity of Idaho’s tax, we follow long-established precedent in relying on the Due Process Clause of the Fourteenth Amendment. See, e. g., Exxon, 447 U. S., at 219, 221-225, 226, 227; Mobil, 445 U. S., at 436-442; Butler Bros. v. McColgan, 315 U. S., at 507, 508; Underwood Typewriter Co. v. Chamberlain, 254 U. S., at 120-121. In view of our decision on due process, it is unnecessary to address appellant’s Commerce Clause argument. In any event, it is elementary that the “States . . . are subject to limitations on their taxation powers that do not apply to the Federal Government.” F. W. Woolworth Co. v. Taxation & Revenue Dept., post, at 363. Cf. Insurance Corp. of Ireland, Ltd. v. Compagnie des Bauxites de Guiñee, 456 U. S. 694, 713 (1982) (Powell, J., concurring in judgment). The question of federal authority to legislate in this area— whether to lay taxes or to delegate such power — is not presented in this case, and we imply no view as to it.
  The dissenting opinion reflects profound — though unexpressed — dissatisfaction with the unitary-business principle, even though it was firmly established by more than a half a dozen decisions of this Court prior to Mobil and Exxon. See n. 14, supra. The dissent purports to rely on these recent cases, and yet its basic arguments — in practical effect — would seriously undermine their force as precedents. It relies primarily on considerations quite different from those identified as controlling in Mobil and Exxon. The dissent does not deny that ASARCO’s subsidiaries were discrete business enterprises; rather it submits that they were engaged “in the same general line of business.” Post, at 335. It notes — though the relevance is not obvious — that the management of ASARCO had special knowledge of the types of business engaged in by these subsidiaries. Post, at 336-337. The dissent also perceives a relationship between Idaho and the investment income simply because ASARCO has the use in its business of income from whatever source it may be derived. Post, at 337-339. Finally, it emphasizes the limited amount of open market buying and selling of products between ASARCO and the companies in which it has invested funds. See Parts III-A and III-B, supra.
  In Mobil, in applying the unitary-business principle, the Court stated that the question is whether “the [investment] income was earned in the course of activities unrelated to the sale of petroleum products” in the State seeking to tax the income. Our decision went against Mobil Oil Corp. because we found that its “foreign activities [were] part of appellant’s integrated petroleum enterprise,” and because the subsidiaries in question were not shown to operate as “discrete business enterprise[s].” 445 U. S., at 439. In this ease, in sharp contrast, the record establishes that each of the three partial subsidiaries in question operated a “discrete business enterprise” having “nothing to do with the activities of [ASARCO] in the taxing State.” Id., at 442.
  As we recognize in this opinion, these cases are decided on their facts in light of established general principles. The most comprehensive discussion of the factors that are relevant is contained in our recent decisions in Mobil and Exxon. In both of those cases, that we follow today, the States prevailed because it was clear that the corporations operated unitary businesses with a continuous flow and interchange of common products. ASARCO has proved that these essential factors are wholly absent in this case. It is late in the day to confuse this important area of state tax law by rewriting the standards of Mobil and Exxon.
  ASARCO has not challenged Idaho’s taxation of interest and capital gains income other than that attributable to the five corporations discussed in the text. Brief for Appellant 26. We do not intimate views on such matters.
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