Does a corporate limited partner in an investment fund apportion or allocate its California income?

The unitary question, and why a blocker usually wins it

Unity is tested under California's general standards, the three unities of ownership, operation, and use (Butler Brothers v. McColgan (1941) 17 Cal.2d 664) and the contribution or dependency test (Edison California Stores, Inc. v. McColgan (1947) 30 Cal.2d 472), applied to the relationship between the partner's activities and the partnership's business; for this purpose the regulation tests unity disregarding ownership requirements (Cal. Code Regs., tit. 18, section 25137-1(f), (g)). For an operating company holding a stake in a partnership that extends its own business, unity is a live fight. For a blocker whose sole activity is holding a limited partner interest, with no employees, no part in management, and no right to control the fund, the Franchise Tax Board's own guidance points toward a non-unitary answer. Limited partners "are not likely to be considered unitary" with limited partnerships in which they hold limited interests, and in the ruling's examples control, not the percentage owned, drove the result: a 60 percent passive limited partner was not unitary, while 20 percent interests came out both ways depending on control (FTB Legal Ruling 2021-01 (Oct. 25, 2021), Situations 1B, 1C, 5A and 5B, citing Appeal of Gasco Gasoline, Inc., 88-SBE-017 (June 1, 1988), where the State Board of Equalization held that limited partnership interests in oil-drilling partnerships, with no management role and no operational integration, were passive investments and not part of the partner's unitary oil business). The facts that carry that answer, no participation in management, no control over the general partner, and no business activity other than the holding, belong in any audit response, stated affirmatively.

The doing-business cases rest on the same control facts. In Appeals of Amman & Schmid Finanz AG (96-SBE-008, Apr. 11, 1996), the State Board of Equalization held that foreign corporations were not doing business in California solely because they held limited partnership interests in partnerships doing business here, reasoning that a general partner has no agency rights over the obligations or the property of the limited partners, and that a limited partner is not bound by partnership obligations unless it took part in control (citing Corporations Code section 15632). Swart Enterprises, Inc. v. Franchise Tax Board (2017) 7 Cal.App.5th 497 relied on Amman & Schmid and held that an out-of-state corporation holding a 0.2 percent interest in a manager-managed LLC was not doing business in California "based solely on its minority ownership interest." The Franchise Tax Board's narrow reading of Swart for LLC members (Legal Ruling 2014-01; Notice 2017-01; Legal Ruling 2018-01) is now under court-ordered correction: on September 10, 2026, the San Francisco Superior Court gave final approval to a class settlement in Bahl Media, LLC v. Franchise Tax Board (No. CGC-16-554150) under which the FTB will correct and clarify those three documents. The settlement covers LLC members only, not limited partnership interest holders; the court's compliance hearing is set for March 12, 2027, and as of October 10, 2026 the FTB had posted no corrected guidance.

Both cases arise under the doing-business statute rather than unity doctrine. The absence of agency and management rights they turn on also bears on centralized management and functional integration in the unitary analysis, but the doing business question does not decide whether the blocker's California income is taxed. A corporate limited partner that is not doing business in California remains subject to the corporation income tax on its net income derived from sources within this state (Rev. and Tax. Code section 23501(a)). The appellants in Amman & Schmid had reported their distributive shares as income taxable under section 23501, and the State Board of Equalization reversed only the FTB's treatment of them as doing business for franchise tax purposes. The doing business question therefore decides which tax applies and whether the minimum franchise tax is owed, not whether the partner's California-source share is taxed; that share is computed under section 25137-1 either way. A blocker commercially domiciled in California is doing business here regardless of its activity level (Rev. and Tax. Code section 23101(b)(1)), and the interplay between the bright-line doing-business thresholds and a partner's share of the partnership's California factors is the subject of a companion article on factor-based nexus for passive investors.

Unity also does not decide whether income is apportioned or allocated. Whether or not the partner is unitary with the fund, its distributive share of the fund's business income remains business income; a non-unitary answer changes which factors apportion it (the fund's own, under subsection (g)), not whether it is apportioned (Cal. Code Regs., tit. 18, section 25137-1(a), (g)). Nonbusiness items reach the allocation statutes in either case (section 25137-1(b)). Under the nonunitary rule, the partnership's business income is apportioned by the partnership's own factors and formula under sections 25128, 25128.5, and 25128.7 (section 25137-1(g)(1)), and for taxable years beginning on or after January 1, 2025, savings and loan activities and banking or financial activities no longer qualify a taxpayer for the three-factor formula of section 25128(b) (Rev. and Tax. Code section 25128(c)(2)). The regulation also states that section 23040 is not applicable to the partnership computation, so the analysis runs on section 25137-1's own track. The current text dates from amendments operative January 1, 2019, which extended the rules to lower-tier partnerships, added the section 23040 sentence, clarified that the business or nonbusiness determination is made at the partnership level, required sales between a unitary partnership and members of the partner's combined reporting group to be eliminated from the sales factor, and changed the measure of the partner's interest for factor purposes from capital to profits (section 25137-1(f)(4)). Those amendments apply only as of their effective date, so an audit year before 2019 should be checked against the prior text (section 25137-1(j)).

Classification happens below, allocation happens above

The second discipline is respecting where each determination is made. Whether a K-1 item is business or nonbusiness income is a legal determination made at the partnership level, by reference to the partnership's trade or business, and the answer tiers up through however many partnership layers sit between the fund and the corporate partner (Cal. Code Regs., tit. 18, section 25137-1(a)). The label on the partnership's return does not control; the statute does. For a nonunitary partner, ordinary business income and rental items arrive characterized and apportioned on the partnership's factors; a unitary partner instead combines its share of the income and of the factors with its own (section 25137-1(f)). Separately stated portfolio items, interest, dividends, and gains on securities, take their character from the partnership's trade or business. Business income includes income from intangible property whose acquisition, management, and disposition are integral parts of the taxpayer's regular trade or business operations (Rev. and Tax. Code section 25120(a)), and the regulation treats interest, dividends, and gains as business income where the intangible arises out of, or was created in, the regular course of the trade or business (Cal. Code Regs., tit. 18, section 25120(c)(2) to (c)(4)). For an investment or credit fund, those items are ordinarily business income apportioned on the fund's own factors.

Only items that are nonbusiness income at the partnership level reach the allocation statutes, and the corporate partner's own attributes then decide their destination. Nonbusiness gains on real property go to the property's situs (Rev. and Tax. Code section 25125(a)); gains on tangible personal property go to its situs, or to the commercial domicile where the taxpayer is not taxable in the situs state (section 25125(b)); nonbusiness interest and dividends go to the commercial domicile (section 25126). Commercial domicile is "the principal place from which the trade or business of the taxpayer is directed or managed" (Rev. and Tax. Code section 25120(b)), not the state of incorporation, and because the statute asks where the business is directed or managed, the location of back-office administration is not by itself the answer.

A hypothetical shows the mechanism. Suppose a corporation directed and managed from California holds a limited partner interest in a credit fund, and the fund's return classifies part of its interest income as nonbusiness income. Section 25126 would allocate that interest to California in full, with no factor relief, because the partner's commercial domicile is here. The result is only as sound as the classification underneath it, and for a fund whose business is investing or lending, a nonbusiness classification of its interest income will ordinarily be hard to support at the partnership level.

The exit follows a different rule. If the corporate partner's gain on selling the fund interest is nonbusiness income, it is not allocated to commercial domicile. Section 25125(d) allocates it by the ratio of the partnership's California tangible property at original cost to its total tangible property, or, where more than 50 percent of the partnership's assets are intangibles, by the partnership's sales factor for its first full tax period before the sale. For a fund holding mostly securities or loans, the sales factor measure is the one likely to apply. Nonbusiness gains on other intangibles go to the commercial domicile (section 25125(c)).

One overlay deserves its own look in fund structures. California's investment partnership rule excludes from a corporate partner's California-source income its distributive share of an investment partnership's interest, dividends, and gains from qualifying investment securities, but only where that share is "the corporation's only income derived from or attributable to sources within this state" (Rev. and Tax. Code section 23040.1(a)(1)). The exclusion does not apply to a corporation that participates in the management of the partnership's investment activities, or that is engaged in a unitary business with another corporation or partnership that does so or that has other California-source income (section 23040.1(b)(1)). The partnership must also meet the investment partnership tests: at least 90 percent of the cost of its total assets in qualifying investment securities and the other listed assets, and at least 90 percent of its gross income from interest, dividends, and gains (Rev. and Tax. Code section 17955(c)(1)). The statute contains no commercial domicile condition, but its only-income condition will often decide the question for a California-domiciled blocker: one with any other California-source income, such as nonbusiness interest allocated to its California domicile under section 25126, fails it. For credit funds, the statutory list of qualifying investment securities names loan participations and certain government-agency-secured mortgage-backed securities but does not expressly name originated whole loans (section 17955(c)(3)), so the asset test deserves a reading against the actual loan book. The analysis is worth running before, not during, an audit, because the return positions it produces are structural.

What the audit will test

An examination of a fund blocker can be expected to test three points, none of them the grand theory. The first is consistency. The business or nonbusiness classification and the Schedule R presentation should look the same in every open year; an item that appears as business income in one year and nonbusiness in the next hands the auditor a question about the file rather than the law. A reconciliation of every open year before the first response is inexpensive insurance, because the period under examination can widen. The second is interest expense, which is governed by statute rather than by a consistency judgment. For an apportioning taxpayer, interest expense is offset first against interest and dividend income not subject to apportionment by formula (other than dividends deductible under section 24402), and only the excess reduces apportionable income (Rev. and Tax. Code section 24344(b)). For a blocker with allocated nonbusiness interest, that offset is the rule, not a judgment call; Appeal of B.B.C.A.F. Inc. (2019-OTA-275, nonprecedential) illustrates how a nonunitary holding company's interest expense allocation is litigated. The third is the sourcing theory an auditor may bring if the fund's interest is business income. Regulation 25136-2 assigns interest from loans secured by real property to the state where the property is located and interest from unsecured loans to the borrower's state, and it assigns interest from investments other than loans to California if the investment is managed in California (Cal. Code Regs., tit. 18, section 25136-2(d)(1)(A)2.a to 2.c). For a credit fund, the loan rules turn on which loans are secured by property in which states, and a taxpayer that has mapped the collateral and borrower geography of the loan book, even approximately, can answer that theory on its own facts. For a fund managed in California, however, the non-loan rule can place non-loan interest in the California numerator wherever the issuers sit, so the map will not always show a small California share. Building it from fund-level investment reports is tedious once, and it is better built by the taxpayer than by the examiner.

The deadlines frame all of it. The FTB generally has four years after the return is filed to mail a notice of proposed assessment (Rev. and Tax. Code section 19057(a)). A protest is due within 60 days after the notice is mailed (section 19041(a)), and the FTB's action on the protest becomes final 30 days after it mails notice of that action, which is also the window for an appeal to the Office of Tax Appeals (section 19045(a)). A claim for refund is due by the latest of four years from the date a timely return was filed, four years from the original due date without regard to extensions, or one year from the overpayment (section 19306(a)). A refund suit under section 19382 does not require a prior appeal to the Office of Tax Appeals; it must be filed within the periods in section 19384, may be brought once six months pass without the FTB's notice of action on the claim (section 19385), and is limited to the grounds the claim stated.

Practice notes

For a corporate entity holding a fund interest with a California connection, the sound practice is a four-document file built before the first return goes out: a unitary memo stating the no-participation, no-control facts and tying them to Legal Ruling 2021-01; a classification schedule tying each K-1 line to business or nonbusiness treatment with the partnership-level rationale; a commercial domicile analysis stating where the entity is directed or managed and why; and, for credit funds, a collateral and borrower-situs summary refreshed as the portfolio turns. Under audit, the effective response answers the question asked, provides the chain of the structure that explains the income rather than the whole organizational chart, and states the affirmative facts that carry legal weight, the absence of management rights above all, in the first written response so they frame everything after. Before an all-to-California allocation is adopted, or defended under examination, the partnership-level classification that supports it deserves testing and the alternatives deserve pricing: for a California-domiciled blocker, allocation of nonbusiness items under section 25126 can produce a larger California answer than apportionment would, and where the numbers are material, the structural questions (where the entity is directed or managed, and whether the investment partnership rule's conditions can be met) are levers to examine prospectively and deliberately rather than mid-audit. G&G State Tax Group provides income classification and apportionment analysis for corporate partners in investment funds alongside its state and local tax practice.