50 Percent Rule: Ownership and Sanctions
One of the most consequential — and most misunderstood — concepts in sanctions compliance is that an entity can be fully blocked even though its name appears on no sanctions list. This is the effect of OFAC's 50 percent rule. If you screen only against the published lists, you will miss a large category of blocked parties. Understanding the rule, and especially how ownership aggregates, is essential to getting sanctions screening right.
What the 50 percent rule says
The US Office of Foreign Assets Control (OFAC) maintains the Specially Designated Nationals (SDN) list of blocked persons. Its guidance states that any entity owned 50 percent or more, in the aggregate, by one or more blocked persons is itself considered blocked — whether or not that entity is named on the SDN list. In other words, the sanction flows down through ownership. A subsidiary that a sanctioned parent owns half or more of is treated as if it were listed, and dealings with it are prohibited to the same extent.
The rule is about ownership, expressed as an equity or property interest. It is deliberately a bright-line test at 50 percent: at or above, the entity is blocked; below, it is not automatically blocked by this rule (though other concerns may apply).
The aggregation trap
The single most important nuance is the phrase "in the aggregate." Ownership by multiple blocked persons is added together. If two different SDNs each own 30 percent of a company, neither stake alone reaches 50 percent — but together they hold 60 percent, so the company is blocked. This is a common way sanctioned parties try to stay under the radar: split ownership across several designated individuals or entities so no single stake trips the threshold.
Screening tools that check each owner's stake individually will miss this. Correct analysis sums the interests of all blocked owners before comparing to the 50 percent line.
Layered ownership
The rule also applies through chains, and here the math gets subtle. Consider Company C, owned 50 percent by Company B, which is in turn owned 50 percent by an SDN. A naive multiplication (50% × 50% = 25%) suggests C is not blocked. But OFAC guidance treats the chain differently: because the SDN owns 50 percent of B, B itself is blocked under the rule. B is now a blocked person. And B owns 50 percent of C — so C is also blocked. Blocked status propagates down the chain: once an intermediate entity crosses the 50 percent threshold, it becomes a blocked person whose own ownership then counts fully at the next level.
What compliance teams must do
The rule turns sanctions screening into an ownership-analysis problem, not just a name-matching one:
- Collect beneficial-ownership data on entity customers and counterparties, not just their names.
- Identify every owner that is a blocked person, and aggregate their stakes before testing the 50 percent threshold.
- Walk ownership chains, promoting any intermediate entity to blocked status once it hits 50 percent and re-testing downstream entities.
- Treat a blocked-by-ownership entity exactly as a listed SDN: block property and reject prohibited dealings.
- Refresh the analysis as ownership changes and as new designations are added — a previously clean entity can become blocked when an owner is listed.
Practical cautions
OFAC has warned that parties should be cautious even below 50 percent, since a blocked person with a significant minority stake may still exercise control, and other authorities apply their own tests (the EU and UK use control-based standards alongside ownership). The rule is specific to ownership, so control exercised without equity may need separate assessment. The overarching takeaway is that name-list screening alone is insufficient: without ownership data and aggregation logic, an institution can transact with a fully blocked entity while believing it is clean because the name was not on any list.
Key takeaways
- OFAC's 50 percent rule blocks any entity owned 50% or more, in aggregate, by blocked persons — even if the entity is not listed.
- Aggregate the stakes of all blocked owners before testing the threshold; separate sub-50% stakes can combine to cross it.
- In layered structures, an intermediate entity that crosses 50% becomes blocked, and its ownership then counts fully downstream.
- Screening requires beneficial-ownership data and aggregation logic, not just name matching.
- Stay cautious below 50% (control concerns) and re-run analysis as ownership and designations change.