A mid-sized technology distributor closes a supply agreement with a new reseller in a third market. Weeks later, a routine screening run flags a shareholder in the reseller's ownership chain. The shareholder appears on OFAC's SDN List (OFAC's list of Specially Designated Nationals and blocked persons). The deal is already signed. Payments are pending. The compliance team now faces a question that should have been answered before execution: is this counterparty itself blocked?
Counterparty due diligence under OFAC legal support means identifying, before a transaction closes, whether a counterparty or any entity in its ownership chain is subject to US sanctions prohibitions – including through the 50 percent rule (OFAC's rule treating entities owned 50 percent or more by blocked persons as themselves blocked, whether or not they appear on a published list). As of mid-2026, OFAC operates a strict-liability civil-penalty regime: a violation is a violation regardless of intent, and the penalty calculation begins from the value of the transaction itself.
This page explains what OFAC counterparty due diligence requires, how the test differs from its UK and EU equivalents, where businesses typically go wrong, and how Calder & Vance assists cross-border teams in getting the analysis right before signing.
What does OFAC counterparty due diligence actually require?
OFAC counterparty due diligence requires a structured inquiry into whether a proposed counterparty – and every entity in its direct and indirect ownership chain – is a blocked person, a designated party, or an entity owned 50 percent or more in the aggregate by one or more blocked persons under the applicable sanctions programme. The governing authority is OFAC, operating under IEEPA and related statutory instruments; the prohibition flows automatically from the programme regulations, not from inclusion on a published list.
Three separate questions organise the inquiry. First: does the counterparty appear on any OFAC published list – the SDN List, the Sectoral Sanctions Identifications list, or the Non-SDN Menu-Based Sanctions list? Second: do any owners, directly or through layers, appear on those lists? Third: do any such owners, individually or in the aggregate, hold 50 percent or more of the counterparty?
Screening a counterparty's registered name against a single database satisfies none of these questions on its own. In our experience, the second and third questions are where violations originate – not because businesses fail to screen, but because they screen too narrowly. A tool that queries only the counterparty entity misses a listed minority shareholder whose co-investor pushes the combined holding over the threshold.
The programme-specific element matters too. Sectoral sanctions under some programmes restrict particular categories of transaction – debt tenors, equity dealings, services – rather than imposing a blanket block. A counterparty that is not SDN-listed may still be off-limits for a particular deal structure. Diligence must account for that distinction.
How does the OFAC ownership test compare with OFSI and the EU?
The OFAC ownership test is mechanical: once aggregate beneficial ownership by blocked persons reaches 50 percent or more, the entity is treated as blocked regardless of control, management, or commercial independence. The test does not care whether the blocked owner exercises any operational influence.
Under OFSI and the equivalent EU position, ownership and control (the UK and EU test for whether a non-listed entity is caught through a listed person) operates differently. OFSI's guidance treats an entity as subject to the asset-freeze where a designated person owns more than fifty percent, or controls it – including through rights, arrangements, or influence that fall short of majority ownership. The EU position under the applicable Council regulations applies a similar dual-pronged approach: majority ownership or effective control.
The practical divergence is significant for cross-border transactions. A counterparty that clears the OFAC fifty-percent test because no single listed person reaches the threshold, and where aggregation across listed co-investors is avoided, may still be caught under OFSI if a listed person holds effective control through board rights or veto powers. Have you run both tests? In a transaction with US-nexus and UK-nexus simultaneously, both need to answer clean.
For businesses that hold licences or deal with counterparties operating across both regimes, we regularly advise on the full stack: OFAC analysis first (the mechanical test), then the OFSI and EU control analysis, then a check against the UN Consolidated List for any remaining exposure. Our OFSI counterparty due diligence service covers the UK leg of that analysis in detail.
What is the procedure for conducting OFAC counterparty due diligence?
A defensible OFAC counterparty due diligence process runs through five defined phases, each building on the last. The depth of each phase scales to the risk profile of the counterparty, the transaction size, and the sanctions programme in play.
Phase 1 – Entity identification. Establish the counterparty's full legal name, jurisdiction of incorporation, registered address, and any trading names or aliases. Discrepancies between commercial documents and corporate-registry records are a red flag in themselves.
Phase 2 – List screening. Run the entity and all known aliases against OFAC published lists – SDN, SSI, NS-MBS – and against the UN Consolidated List. Use an OFAC-approved fuzzy-matching protocol; exact-name matching is not sufficient. Record the search, the parameters, and the result.
Phase 3 – Ownership mapping. Obtain the full ownership structure, ideally to the natural-person level. This means going beyond the counterparty's registered shareholders to identify ultimate beneficial owners, tracing through intermediate holding companies, trusts, and nominee arrangements. Screen each identified owner against the same list set. Apply the fifty-percent aggregation test across all listed persons identified.
Phase 4 – Programme-specific analysis. Determine which OFAC programme or programmes are relevant to the counterparty's nationality, jurisdiction, and sector. Where sectoral restrictions apply, assess whether the proposed transaction falls within the restricted categories regardless of list-screening outcome.
Phase 5 – Risk assessment and escalation. Document the result. Where the analysis is clean, record it with the version of each list used and the date of the search. Where a flag arises – a potential name match, an unverified owner, an ambiguous corporate structure – escalate before proceeding. At this point, involving sanctions counsel is not optional.
The position above covers the standard case. Your facts – the counterparty, the goods, the route, the programme in play – change the analysis. For a review of your specific transaction or counterparty file, contact Calder & Vance at info@caldervance.com.
What are the risk flags that demand closer scrutiny?
Several patterns in a counterparty's profile are, in our practice, consistent precursors to a sanctions exposure that routine screening would miss. Each warrants a deeper look before a transaction proceeds.
Opaque ownership structures. A counterparty with nominee shareholders, multi-layer holding vehicles in jurisdictions with limited public-registry disclosure, or ownership arrangements that shift shortly before a transaction closes should be treated as elevated risk. The fifty-percent rule extends to indirect holdings; a listed person can conceal an aggregated stake across several nominally independent vehicles.
Jurisdictional red flags. A counterparty incorporated or operating in a jurisdiction subject to comprehensive OFAC sanctions programmes triggers heightened scrutiny even where the counterparty entity itself is not listed. The relevant programme regulations may prohibit dealings with persons in that jurisdiction regardless of list status.
Sector-specific restrictions. Counterparties in the energy, financial, or defence sectors in jurisdictions subject to sectoral programmes face transaction-type restrictions on top of entity-level screening. A bank counterparty not on the SDN List may nonetheless be off-limits for specific categories of transaction under the applicable sectoral instrument.
Unverified beneficial ownership. Where a counterparty declines to provide beneficial-ownership information, or where the information provided cannot be independently corroborated against corporate registries or other reliable sources, the gap itself is a red flag. A decision to proceed without resolving it should be recorded and escalated, with legal advice obtained.
Last-minute changes to payment routing or counterparty identity. Instructions to pay a third party, to route funds through an unexpected jurisdiction, or to substitute a different entity at the point of execution are among the clearest operational signals that something in the arrangement warrants sanctions scrutiny.
If a transaction has already been flagged, or a filing has been refused, an early review can preserve options that narrow with time. Contact us at info@caldervance.com to discuss a confidential review.
A common myth about automated screening tools
Many businesses assume that a subscription to a commercial screening database resolves their OFAC due-diligence obligation. It does not. Automated screening is a necessary first step, but it is not a substitute for the ownership analysis, the programme-specific assessment, or the documented escalation process that a defensible due-diligence file requires.
OFAC's strict-liability regime means that a firm cannot point to a clean automated screen as a complete defence if the ownership-chain analysis was never performed. The screen would only confirm that the counterparty entity's name does not appear on a list. It would say nothing about whether a listed person's aggregate stake in that entity crosses the fifty-percent threshold through indirect holdings that the tool was never asked to map.
We have acted for businesses that relied entirely on tool output and later faced an apparent violation because a listed person held a blocking interest through two intermediate holding companies, neither of which the tool was queried against. The lesson is not that tools are useless – they are essential – but that they answer a narrower question than most compliance teams assume. What question, precisely, is your screening tool answering?
How Calder & Vance conducts OFAC counterparty due diligence
Our practice covers the full diligence scope: we screen the counterparty and ownership chain, surface secondary-sanctions risk, and structure the transaction to reduce exposure. For more complex counterparty profiles, we extend the analysis to OFSI and EU ownership-and-control tests, and to UN list status, delivering a consolidated multi-regime view rather than a series of separate reports.
For a single counterparty review, we assess eligibility, conduct the ownership mapping to ultimate beneficial owner level, run the programme-specific analysis, and deliver a written risk assessment with a clear conclusion and a documented evidence file. Where a flag is identified, we advise on the available options: a no-action position supported by the evidence, a specific-licence application, or a restructured transaction.
In a recent matter, a financial-services business sought to onboard a corporate client whose ultimate beneficial owner resided in a jurisdiction subject to an active OFAC programme. The corporate entity itself was not listed. We mapped the full ownership chain, applied the fifty-percent aggregation test, and identified that a co-investor – separately listed – pushed the combined holding to the threshold. The client declined the onboarding before any payment was processed. The matter did not become an enforcement issue.
For businesses that conduct diligence at volume – procurement teams screening dozens of new suppliers each quarter, for example – we design and test the screening logic, map ownership and control protocols, and build escalation procedures calibrated to the risk profile of the business. For the Australian compliance and testing angle on a regional diligence programme, see our compliance audit and testing service.
Where a counterparty is domiciled in Switzerland or operates under Swiss sanctions, the SECO regime adds a further layer to the analysis. Our SECO counterparty due diligence service addresses that position in full.
Related practices
- OFSI counterparty due diligence – ownership-and-control analysis under UK financial-sanctions rules
- SECO counterparty due diligence – Swiss sanctions screening and beneficial-ownership mapping
- Compliance audit and testing – Australia – sanctions screening-logic review and programme stress-testing