Is gain from selling regulatory credits business income or nonbusiness income?

What regulatory credits are and why the label matters

A regulatory credit is a unit a government program issues or recognizes when a regulated party outperforms a standard, which the party can then use, bank or sell to a party that falls short. Federal law provides that when a manufacturer's average fuel economy exceeds the applicable standard in a model year, "the manufacturer earns credits" (49 U.S.C. section 32903(a)), and authorizes the Secretary of Transportation to establish "a fuel economy credit trading program" (49 U.S.C. section 32903(f)(1)). Under the federal renewable fuel standard, renewable identification numbers that have been separated from the fuel "can be transferred any number of times" (40 C.F.R. section 80.1428(b)(2)). California's Low Carbon Fuel Standard defines credits and deficits as "the units of measure used for determining a regulated entity's compliance" with the program's carbon intensity requirements, denominated in metric tons of carbon dioxide equivalent (Cal. Code Regs., tit. 17, section 95481(a)), and governs their transfer in section 95487. The common thread is that the credit exists because of the holder's regulated activity and has value because another regulated party needs it.

The classification decides where the gain is taxed. Business income is apportioned by formula among every state where the seller files. Nonbusiness income is allocated, and a gain on intangible property is allocated to the taxpayer's commercial domicile. California applies that rule under Rev. and Tax. Code section 25125, as the Franchise Tax Board's Multistate Audit Technique Manual describes it: gains and losses from sales of intangible property other than partnership interests are "allocated to the state of the taxpayer's commercial domicile" (MATM 4035). The Multistate Tax Commission's model compact states the same rule (Multistate Tax Compact, Art. IV.6(c)). A seller domiciled in a state with a low rate or no corporate income tax gains from nonbusiness treatment; every other state where it files loses.

The statutory tests

California's definition is the uniform one. Business income is "income arising from transactions and activity in the regular course of the taxpayer's trade or business and includes income from tangible and intangible property if the acquisition, management, and disposition of the property constitute integral parts of the taxpayer's regular trade or business operations," and nonbusiness income is "all income other than business income" (Rev. and Tax. Code section 25120(a), (d), as quoted in MATM 4000 and 4010). The Franchise Tax Board's regulation adds a presumption: "the income of the taxpayer is business income unless clearly classifiable as nonbusiness income" (Cal. Code Regs., tit. 18, section 25120(a), as quoted in MATM 4025 and in Appeals of Amarr Company, 2022-OTA-041P). The manual treats the presumption as allocating the burden of proof, not as ending the inquiry (MATM 4025).

The California Supreme Court held in Hoechst Celanese that the two clauses are independent tests, concluding "that a separate functional test exists." Under the transactional test, the controlling factor is the nature of the particular transaction that generated the income, and the frequency and regularity of similar transactions are relevant (MATM 4010). Under the functional test, the court read "acquisition, management, and disposition" to require that the taxpayer acquire the property, control and manage it, and "transfer, or have the power to transfer, control of that property in some manner." Income is business income under that test if the taxpayer's "acquisition, control and use of the property contribute materially to the taxpayer's production of business income." "Integral" requires "an organic unity" between the property and the business, and the control and use must be part of the taxpayer's "normal or typical business activities." Most important for credits, the court held that under the functional test "the extraordinary nature or infrequency of the income-producing transaction is irrelevant." The Office of Tax Appeals applied that structure in Amarr, a precedential opinion, accepting that a one-time deemed asset sale did not satisfy the transactional test and holding that "the sale will result in business income if it meets the functional test," because "property that generated unitary business income also generates business income when it is sold."

Other states have moved past the uniform wording toward the constitutional limit. The Multistate Tax Commission's model compact, with its 2014 and 2015 recommended amendments, replaces business income with "apportionable income," meaning "all income that is apportionable under the Constitution of the United States" and not allocated under state law, including income from property "if the acquisition, management, employment, development or disposition of the property is or was related to the operation of the taxpayer's trade or business" (Multistate Tax Compact, Art. IV.1(a)). Illinois defines business income as "all income that may be treated as apportionable business income under the Constitution of the United States," and nonbusiness income as all other income except compensation (35 ILCS 5/1501(a)(1), (a)(13)). Wisconsin makes income of a multistate corporation apportionable unless it is nonapportionable income specified in its statute, presumes income from a listed set of sources to be "apportionable as unitary or operational income," and includes the "[s]ale of scrap and by-products" in that list (Wis. Stat. section 71.25(5)(a), (b)). In those states, the constitutional question below is the whole question.

Applying the tests to credit sales

Three invented fact patterns show where the tests land.

A renewable natural gas producer captures methane, upgrades it to pipeline quality and sells both the gas and the environmental attributes the program attaches to it, with credit sales contracted monthly through a marketing desk. The credit sales are part of the business model and recur on a schedule. The transactional test is met on its own terms.

A regional food distributor electrifies its delivery and warehouse equipment for operating reasons, finds that the resulting fuel activity generates credits under a state clean fuel program, and sells the accumulated credits through a broker once every year or two. The transactional argument is weaker, since selling credits is not what the distributor does. The functional test does the work. The distributor acquires the credits through its own operations, controls them in its program account, has the power to transfer them, and earns them only because its equipment runs on qualifying fuel in the course of its business. Under Hoechst the infrequency of the sales does not matter, and the credits have the organic connection to the business the court required. The result is business income.

The same distributor later sells its fleet, exits the program and sells its banked credits in one transaction. That looks like the extraordinary event that fails the transactional test, and it does. Under Hoechst and Amarr, though, a one-time disposition of property that was integral to the business still produces business income under the functional test, and the Franchise Tax Board's manual takes the position that liquidation gains can be business income under that test (MATM 4030). An exit from the activity does not convert the banked credits into investment property.

Wisconsin's statutory list offers a useful comparison. Scrap and by-products are things a business produces without intending to sell them as its main product, and the statute presumes the income from selling them to be apportionable (Wis. Stat. section 71.25(5)(a)). Credits generated by operations share those features. That comparison is analysis, not a holding.

The constitutional layer: operational function

A state's statute cannot reach further than the Constitution allows. The Supreme Court held in Allied-Signal, Inc. v. Director, Division of Taxation, 504 U.S. 768 (1992), that "the payee and the payor need not be engaged in the same unitary business as a prerequisite to apportionment in all cases"; what is required is "that the capital transaction serve an operational rather than an investment function" (504 U.S. at 787). The Court traced that distinction to Container Corp. of America v. Franchise Tax Board, 463 U.S. 159, 180 n.19 (1983), which had cited Corn Products Refining Co. v. Commissioner, 350 U.S. 46 (1955) (504 U.S. at 788). Corn Products is a federal capital asset case: the Court held that a manufacturer's corn futures, bought to protect its supply of raw material, produced ordinary income because they were an integral part of its manufacturing business, reasoning that "the definition of a capital asset must be narrowly applied." In MeadWestvaco Corp. v. Illinois Department of Revenue, 553 U.S. 16 (2008), the Court confined the operational function concept: it was "not intended to modify the unitary business principle by adding a new ground for apportionment," and it recognizes that "an asset can be a part of a taxpayer's unitary business" even where no unitary relationship exists between payor and payee.

Credit sales fit that description. The buyer of a credit is an unrelated regulated party, so there is no unitary relationship between payor and payee, and none is needed. The question is whether the credit was part of the seller's own unitary business, and a credit the seller earned through its own production, fleet or fuel activity was. The same is true of credits a company buys to cover its own compliance needs and later sells as surplus: in Corn Products terms, the purchase was part of the everyday operation of the business, a hedge against a compliance shortfall rather than a bet on price.

The case that comes out differently is the company that buys credits with no compliance need, through a treasury or investment affiliate, holds them for appreciation and sells them on its own timetable. That holding looks like an investment function, and in a uniform-act state the transactional test fails unless trading is a regular activity. Even there, the argument is not free of doubt. If the trading is frequent, it becomes a business activity of its own; if the credits sit inside a combined group with an operating company that uses them, the unitary analysis reaches them. The library's article on the unitary business principle covers that analysis. A company that wants nonbusiness treatment for a credit portfolio needs a record that keeps the portfolio separate from operations in fact.

The one tribunal decision, and what is still open

The question has reached a tax tribunal at least once. In American Honda Motor Co., Inc. v. Wisconsin Department of Revenue, Docket No. 19-I-227 (Wis. Tax App. Comm'n Nov. 29, 2021), as the Department of Revenue summarized the ruling, the taxpayer earned environmental credits under a regulatory mileage and emission reduction credit program, sold its excess credits, and reported the proceeds as nonapportionable income on its fiscal 2015 Wisconsin combined return. The Department recharacterized the proceeds as apportionable on audit. The Commission agreed with the Department, finding the income apportionable under the unitary, operational and taxable presence tests, on reasoning that the credits arose from regulatory compliance tied to the group's core business and were an integral part of its operations rather than an isolated investment (Wisconsin Tax Bulletin 216, Report on Litigation (January 2022)). The Department's summary reports that the taxpayer appealed. The Commission's posting of higher court outcomes listed no decision in the case as of October 14, 2026, and the later history could not be confirmed.

No California authority addressing regulatory credit sales by name was located. The general authorities above point one way, and the Franchise Tax Board's presumption puts the burden on the taxpayer, so a nonbusiness position in California rests on facts showing an investment holding.

One drafting point remains open. The functional test speaks of income from "tangible and intangible property," and some program rules describe credits in compliance terms rather than as property, as the Low Carbon Fuel Standard does when it defines credits as "units of measure" (Cal. Code Regs., tit. 17, section 95481(a)). No authority located addresses whether that wording keeps a credit outside the functional test. The argument has limited reach: neither the transactional test nor the model compact, Illinois or Wisconsin definitions depends on the property label, and a credit the holder can sell behaves as property in every respect the functional test examines.

After classification: the sales factor, and a tax on the credit itself

Business income classification does not end the analysis, because the receipts may also affect the sales factor. In California, the occasional sale rule excludes gross receipts that are substantial and arise from an occasional sale of a fixed asset or other property held or used in the regular course of business (Cal. Code Regs., tit. 18, section 25137(c)(1)(A), as quoted in Appeals of Amarr Company, 2022-OTA-041P), with sales to the same purchaser in a single year aggregated. A recurring credit seller cannot use the rule; a one-time sale of banked credits on an exit may fall within it. The library's article on merger termination fees covers the mechanics of that exclusion.

Where the receipts stay in the factor, California assigns sales of intangible property "to this state to the extent the property is used in this state" (Cal. Code Regs., tit. 18, section 25136-2(d)). For a complete transfer, use is presumed to be in California to the extent the contract or the taxpayer's books kept in the normal course of business indicate that the purchaser will use the property in California; if that cannot be determined, the location is reasonably approximated, and the last fallback is the purchaser's billing address (section 25136-2(d)(1)(A) to (C)). The regulation does not mention regulatory credits. Applying it, a credit under a California program bought to meet a California compliance obligation points toward California, while a federal credit used against a nationwide obligation calls for approximation. The contract terms describing the buyer's intended use are the evidence the regulation looks to first.

A state can also tax the credit transaction directly. Washington enacted an excise on vehicle manufacturers' surplus zero-emission vehicle credits in 2025: 2 percent of the reported sales price of a credit sold to another manufacturer, and 10 percent of a computed average credit price for each banked credit held for use in a future model year, with manufacturers below a statutory volume threshold excluded (Substitute House Bill 2077, chapter 419, Laws of 2025, sections 4 and 6, effective May 20, 2025). The excise does not answer the income tax classification question in the states where the manufacturer files.

Practice notes

The classification is decided on records, and most of them exist before a tax return is prepared: the program registration and account showing how the credits were generated, the internal approval of each sale, the broker or offtake agreements, the sales history across years, and the accounting presentation of the proceeds. A company that books credit proceeds as revenue, budgets for them and manages them through its operating group will find a nonbusiness position hard to sustain in any state, and the reporting is examined across all of its filing states together, so a position taken in one state is quoted back in the others. Reporting the proceeds as capital gain for federal purposes does not make them nonbusiness income; the state tests ask different questions. Where a credit holding is meant to be an investment, the supporting record is an entity or account separate from operations, no compliance use, and decisions made on investment grounds. For sales factor purposes, contract language identifying where and under which program the buyer will use the credits is the first evidence California's sourcing regulation examines, and a large one-time sale is tested against the occasional sale rule before the factor is computed. G&G State Tax Group provides business and nonbusiness income analysis, apportionment review and audit representation for companies that generate or trade regulatory credits alongside its state and local tax practice.