OFAC 50 Percent Rule: How to Identify Blocked Entities Not on the SDN List

The OFAC 50 Percent Rule says that an entity owned 50% or more by blocked persons is itself blocked. The ownership can be direct or indirect, held by one blocked person or spread across several. Whether the entity appears on the SDN List makes no difference. Most entities the rule blocks appear on no list at all.

Most programs treat sanctions compliance as a list problem. Load the lists, run the names, resolve the matches. The 50 Percent Rule breaks that model, because it blocks entities no list will ever name for you. A designation adds one name to the SDN List. Through the rule, that same designation can silently block five or fifty companies underneath it.

You cannot screen against a list that does not exist. Finding rule-blocked entities is an ownership investigation, and the documented investigation is exactly where most screening programs are thin.

What Does the OFAC 50 Percent Rule Say?

OFAC explains the rule in FAQ 401. The property and interests in property of entities owned 50% or more, directly or indirectly, in the aggregate, by one or more blocked persons are considered blocked. Blocked means the same prohibitions apply as if the entity were named on the SDN List: US persons must freeze its property and may not deal in it without authorisation. Non-US companies can face their own exposure where a transaction touches US jurisdiction.

Two mechanics decide most real cases: aggregation and indirect ownership.

Aggregation means the stakes of several blocked persons are added together. Take a trading company owned 30% by one designated person and 20% by another. No single blocked person holds a majority. Added together, the stakes reach 50%, and the company is blocked.

Indirect ownership means the rule follows the chain entity by entity. Say a designated person owns 60% of a holding company, which makes the holding company blocked. The holding company owns 70% of an operating subsidiary, so the subsidiary is blocked as well. Multiplying through the chain gives the designated person only 42% of the subsidiary. The multiplication is not the test; each blocked link passes blocked status down the chain.

One boundary matters. OFAC's rule turns on ownership, not control. A designated person who runs a company through board seats while owning 49% does not trigger the rule by that alone, although OFAC can still designate the company directly. Keep that boundary in mind; the EU and the UK draw it differently.

Why Is There No List to Screen Against?

OFAC does not publish a list of entities blocked under the 50 Percent Rule. FAQ 401 instead urges parties to a transaction to conduct due diligence on the ownership behind it. The blocked status exists the moment the threshold is met, whether or not anyone has worked it out yet.

That breaks the mechanism screening is built on. Screening compares your business partner names against published list entries; that is the whole method, as explained in how sanctions screening software works. A rule-blocked subsidiary has no entry to compare against. The match engine is not failing. It was never given anything to find.

For example, on Friday, OFAC designates a holding company. Your nightly re-screen picks up the new entry, and Monday's results land. The unlisted subsidiaries come back clean, because their names do not appear on the SDN List and their names have not changed.

The exposure arrived on Friday. The clean result on Monday is accurate about the list and silent about the rule. OFAC does not publish the list. Your program has to produce it.

Why Ownership Data Narrows the Gap but Does Not Close It

Ownership data means the records that show who stands behind a business partner: registry extracts, shareholder filings, and the curated ownership graphs sold by ownership intelligence providers such as Kharon. This data is what turns the 50 Percent Rule from an impossible question into a workable one.

Used well, it does three jobs. It turns a new designation into a set of candidate entities connected to it. It computes the percentages and the aggregation across the chain. And it flags the structures that cross or approach the threshold, so the analyst starts with the right files instead of the whole business partner base.

Picture a new designation touching three of your suppliers. The ownership graph computes two of them at 65% and 80% designated ownership, and one at 48% with a trust holding a further 15%. Without the data, finding those three files could take weeks. With it, the calculation is on the analyst's desk the next morning.

But the calculation is not the conclusion, for three reasons. Registry coverage and freshness vary sharply by jurisdiction, and beneficial owners sit behind nominees, trusts, and foundations that filings do not pierce. A computed 48% is a recorded position on a date, not a verdict on who really holds the interest. And responsibility never transfers to the data vendor: OFAC can impose civil penalties on a strict liability basis, so a wrong number in someone else's database is still your violation.

The data answers the calculation. Only the investigation answers the question.

What the 2026 Sham Transactions Guidance Changes

On 31 March 2026, OFAC issued a Sanctions Advisory on sham transactions and sanctions evasion. The advisory addresses transfers in which a blocked person gives up property on paper while the real interest stays put. Its central point is that OFAC applies functional definitions of interest that look beyond legal formalities to underlying practical and economic realities. A sham transfer therefore does not terminate a blocked interest, however clean the paperwork looks.

The advisory lists red flags that point to a sham. Four matter most for business partner diligence:

• Transfers on commercially unreasonable terms, lacking real consideration or any arm's length character.
• Transfers to family members or close associates, who may be acting as proxies for the blocked person.
• Opaque legal structures, including trusts, straw owners, and front businesses layered without a clear purpose.
• Continued involvement of the blocked person in the use, management, or disposition of the property.

The practical problem is simple. A blocked person can move ownership on paper without giving up the real interest. Shares may be transferred to a relative, a trusted associate, a nominee, or a trust. The recorded percentage drops below 50%, but the blocked person may still direct the asset, benefit from it, or control it through proxies. That is why the calculation cannot close the file by itself. The ownership record changed. The underlying interest may not have.

Now put the red flags next to the calculation. Take a supplier owned 55% by a person designated on a Tuesday. By the following week, 10% has moved to the owner's brother, with no price disclosed. On paper the designated stake is now 45%, below the threshold. Under the advisory, that transfer carries at least three red flags, and the blocked interest may well have survived it.

This is the shift. Before the advisory, some programs treated a sub-50 calculation as the practical end of diligence. Now OFAC has said in writing that where information shows a blocked person previously held an interest, the red flags should be reviewed before the file closes. The advisory is explanatory and does not carry the force of law, but it states plainly how OFAC reads the definitions it enforces.

Under the 2026 guidance, the ownership maths is where diligence starts, not where it ends.

How Do the EU and UK Rules Differ?

The EU and the UK apply the same idea with different mechanics. The EU's Best Practices, updated in July 2024, set the threshold at 50% or more, aggregate the stakes of several designated persons, and treat control as a separate trigger. The UK sets its threshold at more than 50% and does not generally aggregate, though its own control test can still catch an entity.

Take the trading company from earlier, owned 30% and 20% by two designated persons. Blocked under OFAC. In scope under the EU approach. Under the UK ownership test, neither stake reaches the threshold on its own. One structure, three answers: one ownership calculation does not serve every regime.

What a Defensible Ownership Determination Looks Like

A defensible ownership determination is a written record of how the conclusion was reached. It shows what was checked, what was found, how the rule was applied, and who decided, on which date.

The reason it matters is simple. For listed names, the evidence of compliance is the screening audit log. For rule-blocked entities there is no log entry to point to, so the determination record is the only proof the question was ever asked. That is also how reviews work in practice: auditors evaluate decisions, not tools, as set out in what auditors look for in a sanctions compliance program.

A determination that holds up will record five things. The trigger, such as a new designation or an ownership change at an existing business partner. The sources consulted with their dates, and the percentages and aggregation found in them. The red-flag review under the March 2026 advisory, including any transfers timed around the designation. And the conclusion, with the name of the person who made it and the date.

So the practical question for the program is not only "did we run the names?" It is "can we show, for each business partner the designation touched, how we reached the conclusion we reached?"

Risk tiering belongs here. Every business partner connected to a new designation gets the ownership check; tiering decides how deep the investigation goes once the numbers are back, not whether the question is asked. The measurable number to manage is time from a new designation to a documented ownership determination for every business partner connected to it. Where the numbers and the red flags point to a live exposure, the work moves into the sanctions alert investigation process like any other open alert.

A conclusion in an analyst's head clears nothing. A conclusion in the record is what the program can defend.

The Same Problem Is Coming to Export Controls

In September 2025, the US Bureau of Industry and Security adopted the Affiliates Rule, extending certain export-control restrictions to unlisted foreign affiliates of restricted parties. Under the rule, an entity owned 50% or more, directly or indirectly, individually or in aggregate, by Entity List parties, MEU List parties, certain SDNs, or entities already restricted because of ownership can become subject to the same export-control restrictions as its owner.

The rule is currently suspended. BIS suspended the Affiliates Rule from 10 November 2025 through 9 November 2026. Unless BIS extends the suspension or changes course, the rule is scheduled to return on 10 November 2026.

For trade compliance teams, this widens the same question. The ownership behind a business partner can decide export licensing exposure, not only asset-freeze exposure. And again, no published list will name every affected affiliate. A program that builds the determination discipline for the OFAC 50 Percent Rule is building the same muscle it will need for the Affiliates Rule.

Where That Leaves Your Program

The 50 Percent Rule has two moving parts. The first is the calculation: who owns what, in aggregate, through which chain. The second is the investigation that stands behind the calculation: whether the recorded position is the real one, and whether anyone can show how that was decided. Ownership data does the first job at scale. Only your program can do the second.

Manage it with one number: the time from a new designation to a documented ownership determination for every business partner it touches. You cannot screen against a list that does not exist. And you cannot defend a conclusion you never documented.

The SDN List tells you who was designated. Your records have to show who was blocked.