An affiliate company is a business connected to another business through shared ownership or the power to influence its decisions. Under SEC rules, the connection exists whenever one entity “directly, or indirectly through one or more intermediaries, controls or is controlled by, or is under common control with” another.1eCFR. 17 CFR 230.405 – Definitions of Terms That phrasing is broad on purpose. It picks up a tech giant’s web of subsidiaries and two small firms that happen to share an owner. The label matters because it changes how the companies are taxed, what they have to disclose, how antitrust regulators view them, and whether they qualify for programs like SBA-backed loans.
Why the Definition Depends on Which Law You Are Reading
There is no single legal definition of “affiliate.” Securities regulators, accounting standards, and the tax code each draw the line in a different place, and a company can be an affiliate under one and not the other.
The SEC Approach: Control, Not Ownership Percentage
For securities law, SEC Regulation S-X defines “control” as the power to direct a company’s management and policies, whether through voting shares, contracts, or any other means. A subsidiary is simply an affiliate that another entity controls.2eCFR. 17 CFR 210.1-02 – Definitions of Terms Used in Regulation S-X The SEC does not set a fixed percentage. Two companies can be affiliates through a management contract or shared board, with no stock changing hands.
The Accounting Threshold: 20% and 50%
GAAP draws a brighter line. Under ASC 323, owning 20% or more of another company’s voting stock creates a presumption of “significant influence” over its financial and operating decisions. More than 50% establishes outright control, making the owned company a subsidiary. The 20-to-50% band is the classic affiliate zone for accounting purposes: enough ownership to shape decisions, not enough to dictate them. Below 20%, the investor is generally treated as a passive holder unless other evidence suggests otherwise.
The Tax Code: Multiple Definitions at 80% and 50%
The IRS uses still higher thresholds, and more than one of them. Under IRC Section 1504, an “affiliated group” that can file a single consolidated federal income tax return requires at least 80% of both voting power and total stock value.3Office of the Law Revision Counsel. 26 USC 1504 – Definitions A parent that owns 60% of a subsidiary has an affiliate for financial reporting but cannot consolidate on its tax return.
Separately, IRC Section 1563 defines “controlled groups” for other tax purposes. A parent-subsidiary controlled group also uses the 80% test. A brother-sister controlled group exists when five or fewer individuals, estates, or trusts own more than 50% of each corporation, counting only ownership that is identical across the entities.4Office of the Law Revision Counsel. 26 USC 1563 – Definitions and Special Rules These controlled-group rules carry heavily into employee benefits.
Common Affiliate Structures
Parent and Subsidiary
The clearest affiliate arrangement is a parent company that owns a controlling stake in one or more subsidiaries. The parent sits at the top of the chain and directs strategic decisions below it. If a parent owns 70% of a subsidiary’s voting shares, the remaining 30% is a non-controlling interest. That minority stake does not reduce the parent’s control. Alphabet Inc. and its hundred-plus subsidiaries, including Google, YouTube, and Waymo, is the familiar example.
Sister Companies
Two companies are sisters when they share the same parent or common owner but neither owns or controls the other. Their connection runs through the parent, not between them. Under Berkshire Hathaway, GEICO and Dairy Queen are sister companies: both are subsidiaries of Berkshire, but neither has any ownership of the other. The structure is common for isolating business risk, since a lawsuit against one sister does not directly reach the other’s assets.
Joint Ventures
A joint venture is an entity created by two or more companies for a specific project or line of business, with no single venturer controlling it outright. Each partner typically uses the equity method to account for its share. If one partner later acquires enough control to dominate the venture, it stops being a joint venture and becomes that partner’s subsidiary.
Variable Interest Entities
Not every affiliate relationship runs on stock. A variable interest entity (VIE) is a structure where control is measured by financial exposure instead of voting rights. Under ASC 810, a company that has both the power to direct the VIE’s most significant activities and the obligation to absorb its losses, or the right to receive its benefits, must consolidate the VIE on its financial statements. If your company absorbs most of another entity’s financial risk, accounting rules may treat you as its parent regardless of how many shares you hold.
Significant-Influence Affiliate
A pharmaceutical company that buys a 25% stake in a biotech startup, picks up a board seat, and shapes research priorities has an affiliate under GAAP without controlling it. The investment goes on the books using the equity method.
What Affiliation Actually Triggers
Consolidated Tax Returns
When a parent-subsidiary group clears the 80% threshold under IRC Section 1504, it can elect to file a single consolidated federal return on IRS Form 1120.3Office of the Law Revision Counsel. 26 USC 1504 – Definitions Profitable members can offset their income with losses of unprofitable members, reducing the group’s total tax. Once made, the election generally binds the group going forward unless the IRS allows the group to discontinue.
Transfer Pricing Between Affiliates
When affiliates sell goods, lend money, or provide services to each other, the IRS requires those transactions to be priced as if the parties were unrelated. This arm’s length standard exists to stop companies from shifting profits into lower-tax entities.5Office of the Law Revision Counsel. 26 USC 482 – Allocation of Income and Deductions Among Taxpayers If a U.S. parent sells inventory to a foreign subsidiary at an artificially low price, the subsidiary’s profits swell at the expense of U.S. taxable income, and Section 482 gives the IRS authority to reallocate that income back. Treasury Regulation 1.482 requires detailed documentation of the methodology, and the penalties for getting it wrong are serious.
Employee Benefit Plans
This is where affiliation catches owners off guard. Under IRC Section 414, all employees of a controlled group of corporations are treated as if they work for a single employer when testing retirement plans for compliance. The same rule applies to unincorporated businesses under common control and to affiliated service groups.6Office of the Law Revision Counsel. 26 USC 414 – Definitions and Special Rules A business owner who runs two companies cannot offer a generous 401(k) to employees of one while excluding the workers of the other. Nondiscrimination testing, vesting, and contribution limits under Sections 401(a), 410, 411, 415, and 416 all apply across the whole controlled group. Ignoring the rule can disqualify the entire plan and trigger back taxes and penalties for every participant.
Antitrust Review
Federal antitrust enforcers treat affiliated companies as a single economic unit. When reviewing mergers and acquisitions, the FTC and DOJ aggregate the sales and market position of all affiliates, and a deal that clears the annually adjusted size-of-transaction threshold requires a pre-merger notification under the Hart-Scott-Rodino Act before closing.7Federal Trade Commission. New HSR Thresholds and Filing Fees for 2026
Section 8 of the Clayton Act separately prohibits the same person from serving as a director or officer of two competing corporations whose capital, surplus, and undivided profits exceed a threshold that is also adjusted each year.8Federal Register. Revised Jurisdictional Thresholds for Section 8 of the Clayton Act The prohibition does not apply if the competitive sales of either company fall below a safe harbor, or if those sales represent less than 2% of either company’s total revenue.9Office of the Law Revision Counsel. 15 USC 19 – Interlocking Directorates and Officers Companies with affiliate networks that span multiple industries need to audit board rosters regularly.
SBA Small Business Eligibility
For small businesses, the SBA’s affiliation rule is often the most consequential piece of all. When deciding whether a company qualifies as “small” for government contracts or SBA-backed loans, the agency combines the revenue and employees of the applicant with those of all its affiliates.10eCFR. 13 CFR 121.103 – How Does SBA Determine Affiliation A company with 40 employees that looks small on its own can be disqualified by an affiliate with 300 more.
The SBA’s definition is wide. It looks at stock ownership, common management, contracts, and the “totality of the circumstances.” A minority shareholder who can block board actions may be found to exercise negative control. Stock options and convertible securities are treated as already exercised, and the SBA will not credit an attempt to divest ownership solely to escape an affiliation finding. There are a few exceptions. Businesses owned by licensed Small Business Investment Companies are not automatically affiliated with those investors, and firms in an SBA-approved mentor-protégé arrangement are not treated as affiliates of their mentor solely because of that assistance.10eCFR. 13 CFR 121.103 – How Does SBA Determine Affiliation
Financial Reporting
How an affiliate shows up on your financial statements depends on your level of control. When a company controls another, generally above 50% ownership, GAAP requires full consolidation: the parent combines 100% of the subsidiary’s assets, liabilities, revenue, and expenses into its own statements, then eliminates intercompany transactions so the group reports as one economic unit, with any non-controlling interest shown separately.
Significant influence without control (the 20-to-50% range) uses the equity method. The investor records its share of the affiliate’s net income or loss as a single line item, and the carrying value of the investment is adjusted each period for the investor’s share of earnings. The affiliate’s individual assets and liabilities do not appear on the investor’s balance sheet.
Either way, FASB ASC Topic 850 requires disclosure of material transactions between affiliates: the nature of the relationship, the types of transactions, and the dollar amounts. The point is that a deal between related parties may not be priced the way an arm’s length deal would be, and investors need to know.
When the Structure Fails
Piercing the Corporate Veil
The whole point of separate affiliate entities is to contain liability, so a lawsuit against one company does not reach the assets of its parent or sister. Courts will respect that separation, but not when it is a fiction. If a subsidiary is really an alter ego of its parent, a court can pierce the corporate veil and hold the parent directly responsible for the subsidiary’s debts. The usual red flags: commingled bank accounts, no separate board meetings, shared office space without an intercompany lease, and the parent making day-to-day decisions for the subsidiary. The defense is unglamorous. Keep distinct books, hold regular board meetings for each entity, sign contracts in the correct name, and keep funds in separate accounts.
Transfer Pricing Penalties
When the IRS finds that intercompany pricing is not at arm’s length, the consequences go beyond recalculating the tax. A “substantial valuation misstatement” (a transfer price 200% or more, or 50% or less, of the correct arm’s length price) carries a 20% penalty on the underpayment. A “gross valuation misstatement” (400% or more, or 25% or less) doubles that to 40%. A separate net adjustment penalty applies when total Section 482 adjustments exceed $5 million or 10% of gross receipts, rising to 40% once adjustments exceed $20 million or 20% of gross receipts.11eCFR. 26 CFR 1.6662-6 – Transactions Between Persons Described in Section 482 For companies with meaningful intercompany activity, contemporaneous transfer pricing documentation is the main defense.