OFAC Sanctions Screening for U.S. Private Funds: The 50 Percent Rule and the Cost of Getting It Wrong

The Obligation That Does Not Care Whether You Knew

Most U.S. compliance obligations have an intent element or a reasonableness standard. You are expected to act in good faith, to design controls that are reasonably calculated to work, and to be judged on whether your program was sensible given what you knew.

Sanctions are different. Civil liability under the economic sanctions programs administered by the Office of Foreign Assets Control is strict. A U.S. private fund that accepts a capital commitment from a blocked person has violated the sanctions regardless of whether it screened, whether the name appeared on any list it checked, or whether the ownership structure made the connection genuinely difficult to see.

That asymmetry (unlimited obligation, imperfect information) is the defining feature of sanctions compliance for private funds. And it is made substantially harder by a piece of interpretive guidance known as the 50 Percent Rule, which extends blocking to entities that appear on no list at all.

This article explains what the rule requires, why it is fundamentally an ownership-data problem rather than a name-screening problem, and how funds should design controls that address it.

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The Basic Framework

OFAC administers dozens of sanctions programs under authority delegated from the President, principally under the International Emergency Economic Powers Act. The programs vary enormously in structure, but the core mechanics are consistent.

Blocked persons. The Specially Designated Nationals and Blocked Persons List identifies individuals, entities, vessels, and aircraft whose property and interests in property are blocked. U.S. persons are generally prohibited from engaging in any transaction with them.

Other restricted lists. The Sectoral Sanctions Identifications List, the Non-SDN Menu-Based Sanctions List, the Foreign Sanctions Evaders List, and the Correspondent Account or Payable-Through Account Sanctions List each impose narrower restrictions. Screening only the SDN List leaves gaps.

Jurisdictional sanctions. Comprehensive programs prohibit most dealings involving certain countries or regions regardless of whether any specific party is designated.

Who is bound. All U.S. persons: U.S. citizens and permanent residents wherever located, entities organized under U.S. law including foreign branches, and any person physically in the United States. Certain programs reach foreign subsidiaries of U.S. entities. Non-U.S. persons can face secondary sanctions or liability for causing a U.S. person to violate.

What happens on a match. Blocked property must be blocked, not merely rejected. Funds must be placed in a blocked interest-bearing account, and a report filed with OFAC within ten business days. Rejected transactions carry their own reporting requirement. Getting this wrong, returning funds to a blocked person rather than blocking them, is itself a violation.

Civil penalties under IEEPA run to the statutory maximum per violation or twice the value of the transaction, whichever is greater, adjusted annually for inflation. For a fund that accepted a $5 million commitment, the arithmetic becomes serious quickly.

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The 50 Percent Rule

In August 2014, OFAC issued revised guidance stating that any entity owned, directly or indirectly, 50 percent or more by one or more blocked persons is itself blocked, whether or not it appears on the SDN List.

Four features of this rule make it operationally demanding.

It aggregates

Ownership by multiple blocked persons is added together. If Blocked Person A owns 30 percent of an entity and Blocked Person B owns 25 percent, the entity is 55 percent blocked-owned and is itself blocked, even though neither owner individually reaches the threshold.

This defeats the most obvious structuring response. A designated oligarch cannot simply reduce a holding to 49 percent if an associate who is also designated holds another 10.

It applies indirectly

Ownership is traced through the chain. If a blocked person owns 100 percent of Entity X, and Entity X owns 60 percent of Entity Y, then Entity Y is blocked. The chain can run arbitrarily deep, and OFAC does not publish it.

It does not require designation

The blocked subsidiary is blocked automatically, by operation of the rule. There is no list entry, no notice, and no announcement. A U.S. person transacting with that subsidiary has violated sanctions without ever having a name to screen.

Control is not covered, but is not safe

The rule addresses ownership, not control. An entity controlled but not majority-owned by a blocked person is not automatically blocked. However, OFAC has expressly cautioned U.S. persons to exercise caution with such entities, and the reputational and evidentiary risk of dealing with an entity plainly directed by a designated person is substantial. Treating "49 percent owned" as clearance is a misreading of the guidance.

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Why This Is a Data Problem, Not a Screening Problem

Here is the uncomfortable implication. Name screening, running your investor register against the SDN List, cannot detect a 50 Percent Rule violation, because the blocked entity is not on the list.

To detect it, you must know the ownership structure of every entity you deal with, trace it to natural persons and to intermediate holding entities, and screen each of those. The screening is the easy part. Obtaining reliable ownership data is where the work is.

That difficulty is compounded in the U.S. context by the absence of a usable beneficial ownership registry. FinCEN's Corporate Transparency Act database, once expected to serve this function, was narrowed in 2025 to cover only foreign-formed entities registered to do business in the United States. For a domestic LLC investing in your fund, there is no government source that will tell you who owns it.

The practical consequence is that sanctions compliance and beneficial ownership diligence are the same workstream. A fund that has resolved the ownership of its investor entities to natural persons and screened everyone in the chain has done sanctions compliance. A fund that has screened only the names on its subscription agreements has done something that looks like sanctions compliance and provides considerably less protection.

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Where Private Funds Are Exposed

Sanctions exposure in a fund structure is broader than the investor register.

Limited partners. The obvious surface. Every LP, every LP's beneficial owners, and every authorized signatory. Feeder vehicles and funds-of-funds require looking through to the underlying investors, or obtaining contractual representations and reliance arrangements that are themselves diligence-dependent.

The general partner and management company. Principals, directors, and significant owners of the sponsor itself.

Portfolio companies and their counterparties. A U.S. fund whose portfolio company transacts with a blocked party may have a problem, particularly where the fund exercises control. Diligence at acquisition and monitoring during the hold period both matter.

Service providers and vendors. Administrators, custodians, placement agents, and technology vendors are all counterparties.

Payment counterparties. The originating bank and account for each capital contribution. Funds arriving from an institution in a sanctioned jurisdiction present a problem independent of the investor's own status.

Distribution recipients. An investor who was clean at subscription may be designated before the first distribution. Sanctions screening is not an onboarding event.

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Building a Program That Works

OFAC's 2019 Framework for Compliance Commitments identifies five essential elements: management commitment, risk assessment, internal controls, testing and auditing, and training. Translated into private fund operations, that produces the following.

Risk assessment specific to the fund

Generic risk assessments are worthless here. The assessment should identify the jurisdictions from which the fund's capital originates, the jurisdictions in which portfolio investments sit, the use of intermediaries and feeders that obscure the ultimate source of funds, the entity types in the investor base and their typical ownership opacity, and the fund's actual exposure to sectors subject to targeted sanctions programs.

Screening at the right points, against the right lists

Screening should occur at subscription, before every distribution, on every ownership change notified by an investor, and continuously against list updates. It should cover the SDN List and the non-SDN lists, and should be configured for the fund's jurisdictional exposure.

Match logic matters more than most teams appreciate. Exact-match screening fails against transliteration variants, name-order conventions, patronymics, and deliberate misspelling. Fuzzy matching catches these, at the cost of false positives that require a disposition process. A fund receiving hundreds of alerts and clearing them without documented reasoning has created a record that is worse than no record.

Ownership resolution as a first-class control

This is the control that addresses the 50 Percent Rule, and it is the one most often absent.

For each entity investor: obtain a structured ownership declaration covering all layers; corroborate against formation documents, operating agreements, and available registry data; identify all natural persons and all intermediate entities; screen every identified party; and calculate aggregate ownership by any blocked person at each level.

That last step is a genuine computation, not a lookup. Where a blocked person appears anywhere in the chain, aggregate ownership must be traced through the intervening layers to determine whether the 50 percent threshold is met at the level of the entity you are actually transacting with.

Escalation and blocking procedures written in advance

The moment a potential match is confirmed is the wrong moment to be deciding what to do. Written procedures should specify who confirms a match, who authorizes blocking, how funds are segregated into a blocked account, who files the OFAC report within ten business days, and how the situation is communicated, which in the case of a blocked LP raises difficult questions about what can be said to the investor and to other LPs.

Independent testing

Sample-test the screening: take a set of investors, verify that screening actually ran, that the lists used were current, and that alerts were dispositioned with documented reasoning. Test the ownership data: take a set of entity investors and verify that the ownership chain on file is complete and corroborated. Most funds that run this test for the first time find gaps.

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The Automation Argument

There is no plausible manual process that satisfies the 50 Percent Rule at scale.

Consider a fund with 120 LPs, of which 70 are entities, with an average of two ownership layers and three owners per layer. That produces roughly 500 parties requiring screening, ownership data, and documentation, and the list against which they must be screened changes constantly, sometimes multiple times per week during periods of geopolitical escalation.

Doing this once at onboarding is a project. Doing it continuously is not achievable by hand.

Automated systems address this by holding the ownership graph as data rather than as documents, rescreening every node whenever a list changes, generating alerts only where something has actually changed, and maintaining the audit trail as a byproduct rather than a separate task. The compliance officer's role shifts from performing screening to adjudicating alerts and making the judgment calls: whether an ownership representation is credible, whether a partial match is the same person, whether a structure warrants enhanced diligence.

This is the design principle behind VeriKYC's approach to entity onboarding: resolve the structure once, screen everything in it continuously, and produce the evidence file automatically. The 50 Percent Rule is not a screening feature bolted onto name matching. It requires the ownership graph to exist as a queryable object.

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What Regulators Look For

OFAC enforcement actions consistently identify the same failure patterns.

Screening that was performed at onboarding and never repeated. Screening against a stale list snapshot rather than current data. Alert dispositions with no recorded reasoning. Ownership information accepted from the customer without corroboration. Escalation procedures that existed on paper but were not followed. And, repeatedly, no consideration of the 50 Percent Rule at all, with programs that screened names and stopped.

Conversely, OFAC's mitigation factors reward the existence of a risk-based compliance program, prompt remedial action, voluntary self-disclosure, and cooperation. A fund that discovers a violation, blocks the property, files the report, self-discloses, and can demonstrate a program that was reasonably designed but imperfectly executed is in a materially different position than one that discovers the violation because OFAC told it.

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Conclusion: Screen the Structure, Not the Signature

The most common sanctions failure in private funds is not sloppiness. It is a category error: treating sanctions compliance as a name-matching exercise performed against the parties who signed documents.

The 50 Percent Rule makes that approach structurally inadequate. The blocked entity you need to identify may have a clean name, an unremarkable jurisdiction of formation, and no presence on any list. Its status derives entirely from who owns it, and that information is not published anywhere.

The only reliable response is to build ownership resolution into onboarding as a required control rather than an occasional enhancement, screen every party in the resulting structure, keep that screening live as lists change, and document the reasoning at every step.

Strict liability is an unforgiving standard. The compensating advantage is that it is entirely clear what is required. The fund that knows who owns its investors, and keeps knowing, has addressed the risk. The fund that knows only who signed has not.