Form 5471 is an information return — it reports a US person's interest in, and the activity of, a foreign corporation. It does not, by itself, compute a tax. But it is one of the most expensive returns to get wrong: under §6038(b) a late, incomplete, or inaccurate Form 5471 carries a $10,000 penalty per foreign corporation per year, with continuation penalties up to an additional $50,000, plus a §6038(c) reduction of the foreign tax credit — and under §6501(c)(8) the assessment statute of limitations for the return generally does not begin to run until the form is filed.
This guide is about the threshold question that precedes the schedules: does an obligation exist for this person, for this foreign corporation, for this year — and in which of the five filer categories? It works that determination the way a preparer should: the statutory building blocks first, then the §958 attribution that actually drives the thresholds, then the five categories, then a step-by-step framework you can apply to a real structure.
In plain terms there is no single "you must file Form 5471" rule. There are five categories, each with a different trigger. Each category, on its own, creates a filing requirement — but the same person can be subject to more than one at once, and filing under the right category (and its schedule set) matters. The work is figuring out which categories — if any — a given US person falls into for a given foreign corporation.
The building blocks
Every category is defined in terms of a handful of statutory concepts. Pin these down and the categories fall out.
"US person" — who can be a filer
The Form 5471 instructions define a US person, for filing purposes, to include a US citizen or resident individual, a domestic partnership, a domestic corporation, and a non-foreign estate or trust (the Category 4 list also reaches certain §6013(g)/(h)-electing nonresident aliens; the Category 5 list does not).
The point that trips up generalists: a domestic partnership or S corporation is tested as the filer at the entity level for the filing-status question. You do not look through it to its partners or shareholders to decide whether it must file. If the partnership itself owns 10% (US-shareholder) or more than 50% (control) of the foreign corporation, the partnership is the Form 5471 filer — regardless of how small any individual partner's slice is. (Whether the income is included is a separate, look-through analysis — see "Owners that are entities" below.)
"US shareholder" — the 10% test (§951(b))
the term "United States shareholder" means, with respect to any foreign corporation, a United States person (as defined in section 957(c)) who owns (within the meaning of section 958(a)), or is considered as owning by applying the rules of ownership of section 958(b), 10 percent or more of the total combined voting power of all classes of stock entitled to vote of such foreign corporation, or 10 percent or more of the total value of shares of all classes of stock of such foreign corporation.
— IRC §951(b)
Example. USP A holds 8% of Foreign Corporation B (FC B) directly, and A's spouse holds another 4%. Under the §318(a)(1) family rules (applied through §958(b)), A is treated as owning 12% — so A is a 10% US shareholder of FC B even though A's own certificate shows 8%.
Three things to hold onto. First, the threshold is 10 percent of vote or value — either one is enough (the value prong was added by the 2017 Act; pre-2018 it was vote only). Second, ownership is measured "within the meaning of section 958(a)" or "by applying the rules of ownership of section 958(b)" — direct, indirect, and constructive ownership all count toward the 10%. Third, US-shareholder status is the gateway to Category 1 and Category 5, and it is the test that decides whether a foreign corporation is a CFC at all.
"Controlled foreign corporation" — the more-than-50% test (§957(a))
the term "controlled foreign corporation" means any foreign corporation if more than 50 percent of— (1) the total combined voting power of all classes of stock of such corporation entitled to vote, or (2) the total value of the stock of such corporation, is owned (within the meaning of section 958(a)), or is considered as owned by applying the rules of ownership of section 958(b), by United States shareholders on any day during the taxable year of such foreign corporation.
— IRC §957(a)
A foreign corporation is a CFC if US shareholders — each one a 10%-or-more owner — together hold more than 50% of vote or value on any day of the year. Stock held by US persons who are not 10% shareholders does not count toward the more-than-50%. So CFC status is a two-step test: identify the 10% US shareholders first (§951(b)), then ask whether those shareholders collectively cross 50% (§957(a)).
Example. FC B is owned 30% by USP A and 25% by USP C — each a 10% US shareholder — with the remaining 45% held by an unrelated foreign investor. The 10% US shareholders hold 55% in total, more than 50%, so FC B is a CFC and A and C are each Category 5 filers. Change the facts so the only US owner is USP A at 8%, and FC B has no 10% US shareholder, is not a CFC on that basis — yet A may still have a PFIC obligation (see Relationships to other regimes and forms).
In plain terms "10% US shareholder" and "CFC" are different questions. A person can be a 10% US shareholder of a foreign corporation that is not a CFC (because the US 10%-owners don't add up to more than half). And a foreign corporation can be a CFC even though no single US shareholder controls it. You have to run both tests.
"Control" for Category 4 (§6038(e)(2); Treas. Reg. §1.6038-2(b))
Category 4 uses a different control concept than the CFC test — it is about a single US person's control, not the aggregate of all US shareholders.
A person is in control of a corporation if such person owns stock possessing more than 50 percent of the total combined voting power of all classes of stock entitled to vote, or more than 50 percent of the total value of shares of all classes of stock, of a corporation. If a person is in control (within the meaning of the preceding sentence) of a corporation which in turn owns more than 50 percent of the total combined voting power of all classes of stock entitled to vote of another corporation, or owns more than 50 percent of the total value of the shares of all classes of stock of another corporation, then such person shall be treated as in control of such other corporation.
— IRC §6038(e)(2)
For Category 4 this control test is applied using §318(a) constructive ownership with the three modifications in Treas. Reg. §1.6038-2(c), and it is met if the person controlled the foreign corporation at any time during that person's tax year — the control test (Reg §1.6038-2(b)) has no continuous-holding or 30-day requirement. (The 30-day "uninterrupted period" rule that the 2017 Act repealed was the §951(a) gate for Subpart F income inclusion — a different test from this filing-status one.)
Example — chained control. Corporation A owns 51 percent of the voting stock in Corporation B. Corporation B owns 51 percent of the voting stock in Corporation C. Corporation C in turn owns 51 percent of the voting stock in Corporation D. Corporation D is controlled by Corporation A. (Control runs through each more-than-50% tier — even though A's indirect economic interest in D is only about 13 percent.)
"Specified foreign corporation" (§965) — for Category 1
Category 1 turns on whether the foreign corporation is or was a §965 specified foreign corporation with §965 earnings or previously taxed earnings still being reported. It is a temporal category tied to the 2017 transition tax, not to current-year ownership alone — see Category 1 below.
The engine: §958 ownership attribution
Every threshold above — 10%, more-than-50%, control — is tested after applying the ownership rules of §958. Directly held shares are only the starting point.
- §958(a) — direct and indirect. A US person owns stock directly, and also owns indirectly the stock held through foreign corporations, foreign partnerships, foreign trusts, and foreign estates, by proportionate attribution up the chain. (Domestic entities are generally not §958(a) conduits — the chain stops at the first US person.)
- §958(b) — constructive. On top of §958(a), the rules of §318(a) apply (with the §958(b) modifications) to attribute ownership constructively — among family members, between entities and their owners (upward and downward), and through options. This is how an individual who holds nothing directly can still be a US shareholder, and how a family group can collectively control a corporation that no single member controls.
- Post-2017 downward attribution. The 2017 Act's repeal of §958(b)(4) turned on downward attribution from foreign persons to related US persons, producing the "foreign-controlled CFC" concept — a corporation that is a CFC only because of that downward attribution — which drives the 1b/1c and 5b/5c subcategories and several filing exceptions. (This is the regime for 2018–2025 tax years; the OBBBA change for tax years beginning after 2025 is below.)
In plain terms the threshold tests are rarely "what shares does my client hold." They are "what shares is my client treated as owning once you run direct, indirect, and constructive attribution across the whole structure." A client who directly holds 8% can be a 10% US shareholder; a client who holds nothing directly can be a filer through family or entity attribution. This multi-tier attribution analysis — across the entire ownership chain, for every US person and every foreign corporation — is exactly the determination PILOT runs automatically from a client's ownership facts.
What OBBBA changed (tax years beginning after 2025)
The year matters. The 2025 reconciliation act (OBBBA, Pub. L. 119-21) §70353 restored §958(b)(4) for foreign-corporation tax years beginning after December 31, 2025, reversing the 2017 repeal. For those years, downward attribution from a foreign person no longer applies in determining US-shareholder and CFC status:
- Many corporations that were "foreign-controlled CFCs" only because of downward attribution cease to be CFCs for post-2025 years — which can switch off the related Form 5471 obligation and the 1b/1c, 5b/5c subcategory framework that existed only because of the repeal.
- To preserve reporting where Congress still wanted it, OBBBA added a new §951B regime — "foreign-controlled foreign corporations" and "foreign-controlled United States shareholders" — a separate, narrower set of rules that can require reporting where the §958(b)(4) restoration would otherwise turn it off.
The takeaway: a structure analyzed for 2024–2025 can produce a different Form 5471 answer for 2026 and later. Re-run CFC status and the filing categories under the rules in effect for the foreign corporation's tax year, and watch for §951B where downward attribution used to drive the result.
The five filer categories
A single US person can fall into more than one category for the same corporation in the same year, and several categories are additive rather than mutually exclusive. Assign every category that applies.
Category 1 — US shareholders of a §965 specified foreign corporation (1a / 1b / 1c)
A US shareholder of a foreign corporation that is or was a §965 SFC, who owned that stock on the last day of the year the corporation was an SFC. Category 1 is temporal: the filer keeps filing only while there is §965 earnings (Schedule J) or §965 previously taxed earnings (Schedule P) still to report; when both cease, Category 1 ends. The three subcategories split on whether the SFC is a foreign-controlled SFC and whether the filer is related to it under the principles of §954(d)(3): 1a residual; 1b unrelated §958(a) shareholder of a foreign-controlled SFC; 1c related constructive-only shareholder of a foreign-controlled SFC.
Category 2 — a US officer or director, only with a triggering acquisition
This is the category most often misstated. A US citizen or resident who is an officer or director of a foreign corporation is a Category 2 filer only when a US person acquires, during the tax year, either (a) stock that meets the 10% threshold (vote or value) with respect to that corporation for the first time, or (b) an additional 10% or more.
Being an officer or director is not, by itself, a filing trigger. Stable ongoing ownership — even ongoing 10%+ ownership — does not create a Category 2 obligation. There must be a qualifying acquisition event during the year by some US person (who need not be the officer or director). When triggered, the obligation attaches to the officer or director. (§6046; Treas. Reg. §1.6046-1.) In practice Category 2 is uncommon, because most engagements have stable year-over-year ownership.
Example. USP A is a director of FC B but owns no stock. Midyear, USP C acquires 15% of FC B, crossing 10% for the first time. C's acquisition makes A a Category 2 filer for the year — even though A owns nothing. Without that acquisition, A's directorship alone would create no filing obligation.
Category 3 — acquisitions, dispositions, and threshold crossings
A US person who, during the year: acquires stock that brings their ownership to the 10% threshold; acquires an additional 10%; disposes of stock dropping below 10%; or becomes a US person while already holding 10%. Category 3 is independent of CFC status — it applies to any foreign corporation — and it is additive: it is not subsumed by Category 4. Category 3 alone carries Schedule O, Part II (the §6046 acquisition/disposition report), and a failure draws the separate §6679 penalty. A common pattern: a §351 or §721 contribution of property for foreign stock that crosses 10% is simultaneously a Category 3 event (and often drives a §351 disclosure / Form 926).
Category 4 — control of a foreign corporation
A US person who controlled the foreign corporation (more than 50% of vote or value, under the §6038(e)(2) / Reg §1.6038-2(b) test, applying §318(a) attribution with the three §1.6038-2(c) modifications) at any time during that person's tax year. Category 4 has the broadest schedule set; where the same person is also a Category 5a filer, the instructions say to check Category 4 only (its schedules are a superset of 5a's).
Category 5 — US shareholders of a CFC (5a / 5b / 5c)
A US shareholder (the §951(b) 10% person) of a corporation that is a CFC at any time during its tax year, who owned the stock on the last day the corporation was a CFC. As with Category 1, the subcategories split on the foreign-controlled CFC gate and §954(d)(3) relatedness: 5a residual (including any US shareholder of a CFC that is not foreign-controlled); 5b unrelated §958(a) shareholder of a foreign-controlled CFC; 5c related constructive-only shareholder of a foreign-controlled CFC. There is no continuous-period (30-day) requirement — CFC status is tested on any day during the year.
A determination framework
Worked in this order, the categories resolve cleanly:
- Map the structure. List every foreign corporation and every US person with an interest, direct or indirect.
- Attribute ownership. For each US person, compute ownership of each foreign corporation after §958(a) indirect and §958(b) constructive attribution — not just directly held shares.
- Run the status tests. Is the person a 10% US shareholder (§951(b))? Is the corporation a CFC (do the 10% US shareholders together exceed 50% — §957(a))? Does any single US person have control (more than 50% — §6038(e)(2))?
- Check current-year events. Did any US person acquire or dispose of stock crossing a threshold this year (Category 3 — and Category 2 if there is also a US officer/director)?
- Check §965 history. Is there §965 SFC earnings or previously taxed earnings still to report (Category 1)?
- Assign every category that applies. Mind the additivity: a controlling shareholder who acquired stock mid-year in a CFC can be Category 3 and Category 4 — and is also a Category 5a filer, reported under the Category 4 box (whose schedules cover 5a's). Map each filer to its subcategory and its schedule set.
In plain terms the answer is a per-person, per-corporation, per-year matrix — not a single yes/no. Build the ownership picture first (with attribution), then read the categories off it. If you would rather not run that matrix by hand for every entity in an engagement, this determination — who files, in which category, with which schedules — is precisely what PILOT produces from the ownership facts, with the authority cited for each conclusion.
Owners that are entities (partnerships and S corporations)
When a domestic partnership or S corporation owns the foreign corporation, the entity itself is tested as the filer for the filing-status question (the §951(b) / §957 / control tests are applied to the entity's own ownership). If the entity clears 10% it is the Category 5 filer; if it clears control it is the Category 4 filer — you do not require any individual partner to clear the threshold.
Inclusion is the opposite analysis. For Subpart F (§951(a)) and GILTI (§951A) income inclusion, a domestic partnership or S corporation is generally treated as an aggregate — the income flows through to the partners/shareholders via Schedule K-2/K-3, and each partner then applies the 10% US-shareholder test at their own level. A partner whose own §958(a) ownership is below 10% is not a US shareholder and has no inclusion, even though the entity files the Form 5471. (A frequent corollary: that same sub-10% partner may have a Form 8621 PFIC obligation for the foreign corporation, because the §1297(d) CFC/PFIC overlap that shields the entity does not reach the partner.)
Relationships to other regimes and forms
Form 5471 never sits alone. Two adjacent questions decide whether it even applies — and whether something else applies instead or in addition.
Is the foreign company actually a corporation?
Form 5471 is for foreign corporations. Before running any of the tests above, classify the entity:
- A per se corporation — a foreign entity on the §301.7701-2(b)(8) list (e.g., a UK plc, a German AG, a French SA) — is always a corporation; no election is available.
- Any other foreign entity is an eligible entity with a default classification under §301.7701-3(b)(2): a corporation if all members have limited liability; a partnership if it has two or more members and at least one member lacks limited liability; or a disregarded entity if it has a single owner that lacks limited liability.
- An eligible entity can then elect out of that default with a check-the-box election on Form 8832 — for example, a single-member entity electing to be a corporation, or a multi-member entity electing corporation status.
The classification changes the form entirely: a foreign partnership points to Form 8865, a foreign disregarded entity to Form 8858, and a 25%-foreign-owned US corporation to Form 5472. (A companion guide on classifying a foreign entity is forthcoming; the determination turns on §301.7701-2 and -3.)
CFC and PFIC — two rules, and "not a CFC" is not the end
A foreign corporation can be in the CFC regime, the PFIC regime, or both, and the interaction matters:
- The overlap rule (§1297(d)). While a person is a US shareholder of a CFC, that corporation is generally not treated as a PFIC as to that person. The CFC reporting (Form 5471) governs, and Form 8621 is generally not also required for the overlap period.
- "Not a CFC" does not mean "nothing to file." A foreign corporation that fails the CFC test can still be a PFIC (the §1297 passive-income or passive-asset test). A US person who owns even a small, non-controlling slice of a PFIC may have a Form 8621 obligation — and a sub-10% partner in an entity that owns a CFC can fall outside §1297(d)'s shield and into Form 8621. Ruling out a CFC is the start of the analysis, not the end. (See the companion guide, Who must file Form 8621, and is the foreign company a PFIC?.)
Exceptions and relief
- Multiple filers of the same information (Treas. Reg. §1.6038-2(j)). One person may file a single Form 5471 covering others, on a constrained basis — a Category 4 filer may cover 4/5a/5b/5c filers; 5a/5b/5c and 1a/1b/1c filers may be covered only within the same subcategory; Category 2 and 3 filers each file their own Schedule O and cannot be covered. The covered person attaches a statement (and its own Schedule P where applicable). The obligation stays on the relieved person until the joint filing actually covers it.
- Constructive-ownership exceptions. Categories 1, 3, 4, and 5 each excuse a filer who holds no direct interest and is a filer solely by constructive ownership from another US person who files reporting all the required information (with a parallel exception for constructive ownership from a nonresident alien).
- "No §958(a) US shareholder" and "unrelated constructive US shareholder" exceptions narrow Category 1/5 filing for foreign-controlled SFCs/CFCs (Notice 2018-13; Rev. Proc. 2019-40 §8.04).
- Dormant corporations. A simplified summary filing is available under Rev. Proc. 92-70.
- §953(d) electing insurance companies that file a US return are treated as domestic and are excepted.
Penalties for getting it wrong
- §6038(b) — $10,000 per foreign corporation per year for failure to furnish the information; if the failure continues more than 90 days after IRS notice, an additional $10,000 for each 30-day period, capped at $50,000 (a $60,000 maximum per corporation per year).
- §6038(c) — a 10% reduction of the §901/§960 foreign tax credit, with further reductions for continued failure.
- §6679 — a separate $10,000 penalty (same continuation mechanic) for failing to file the §6046 information on Schedule O (Categories 2 and 3).
- §6501(c)(8) — the assessment statute of limitations for the entire return generally does not begin until the required information is furnished.
- Criminal exposure (§§7203, 7206, 7207) is possible for willful failures. A reasonable-cause defense (§6038(c)(4); §6664(c)) may apply, and Rev. Proc. 2019-40 §7 provides certain penalty relief.
What Form 5471 is not
Form 5471 reports — it does not compute your client's income. The GILTI inclusion (Form 8992), the Subpart F calculation, the §250 deduction (Form 8993), the foreign tax credit (Form 1118), and — for an applicable CFC with business interest expense — the §163(j) limitation computed on Form 8990 (which attaches to the Form 5471) are separate downstream work that builds on the facts the Form 5471 captures. The first question — and the one this guide answers — is simply whether a Form 5471 obligation exists, for whom, and in which category.