OFAC Sanctions and the SDN List: Primary and Secondary Sanctions Explained

Specially Designated Nationals (SDNs) are people and organisations designated by the US Treasury's Office of Foreign Assets Control under US sanctions programmes. OFAC publishes them on the Specially Designated Nationals and Blocked Persons List, commonly called the SDN List.¹

The SDN List is a United States/OFAC list. “SDN” is not a generic name for every sanctioned party or every sanctions list. A search result is also not proof that the screened party is the listed person.

OFAC does not publish one definitive list of “sanctioned countries”. It administers programmes that range from broad geographically oriented restrictions to targeted, thematic, sectoral and list-based measures. For names and list records, use OFAC's official Sanctions List Search and Sanctions List Service. For a country or region, use OFAC's current Sanctions Programs and Country Information, applicable regulations and authorisations.²

A country, nationality, residence or place of incorporation does not by itself determine the applicable restriction or the outcome for a customer or transaction.

What is OFAC?

The Office of Foreign Assets Control (OFAC) is part of the US Department of the Treasury. It administers and enforces economic and trade sanctions based on US foreign-policy and national-security goals.³

OFAC sanctions can target countries, regimes, people, organisations, sectors and activities. The applicable programme and regulations determine the restrictions; there is no single legal consequence attached to every OFAC record.

What are secondary sanctions?

Secondary sanctions are programme-specific measures that can expose certain non-US persons to US sanctions consequences for specified conduct, even without the same direct US nexus that makes an activity subject to a primary prohibition. They do not extend every OFAC prohibition to every non-US business, and they do not create one universal test or consequence.⁴

Depending on the authority, possible consequences can include blocking, non-blocking measures, or restrictions on opening or maintaining US correspondent or payable-through accounts. The relevant statute, Executive Order, regulation, determination, programme guidance, facts and authorisations must be checked before reaching a conclusion.⁵

Primary versus secondary sanctions

This is an explanatory comparison, not a universal statutory taxonomy. Some direct US prohibitions can apply to non-US conduct, including causing a US person to violate sanctions or evading applicable rules. Separately, secondary-sanctions authorities can create additional programme-specific exposure.⁴

How to identify the actual secondary-sanctions authority

Reviewed: 12 September 2026.

Under one current Russia authority, for example, EO 14024 as amended by EO 14114 can expose certain foreign financial institutions to measures for specified transactions or services involving Russia's military-industrial base. OFAC explains that consequences can include blocking or correspondent-account restrictions, while authorised or exempt activity can change the analysis.⁵ This is one programme example, not a global definition of secondary sanctions.

What is the OFAC SDN List?

OFAC's SDN List identifies designated people, companies, groups and other targets. It also identifies blocked vessels and aircraft. Property and interests in property of SDNs that are in the United States or in the possession or control of US persons are generally blocked, and US persons are generally prohibited from dealing with SDNs, subject to applicable regulations, licences and authorisations.¹

OFAC describes the SDN List as including people and companies owned or controlled by, or acting for or on behalf of, targeted countries, as well as parties designated under programmes that are not country-specific.¹ The list has no predetermined update timetable.⁶

Where can you find and search the current SDN List?

Use OFAC's Sanctions List Service for current downloads and the official Sanctions List Search.⁷ The search tool uses fuzzy logic and can return potential matches across the SDN List and OFAC's non-SDN lists.

OFAC does not recommend one universal match-score threshold. An organisation should configure and investigate results in line with its risk assessment, applicable obligations and procedures.⁸

SDN List versus OFAC non-SDN lists

The SDN List is generally a blocking list. OFAC also maintains non-SDN lists that can impose different, more specific restrictions. A record therefore does not answer the legal question without identifying the list, programme, regulations and facts.

Does OFAC publish a list of sanctioned countries?

No. OFAC states that it does not maintain a specific list of countries with which US persons cannot do business.² Some programmes are broad and geographically oriented; others target particular people, entities, sectors or activities across jurisdictions. Not every programme requires blocking, and the presence of a country-named programme does not mean every person or business connected with that country is sanctioned.

Use the live OFAC programme index rather than a copied country table. Programme pages, restrictions and authorisations change; this source navigator was last verified on 11 September 2026.

Broad, selective and non-blocking programmes

OFAC programmes can be comprehensive or selective and can use blocking, trade restrictions or narrower activity-based prohibitions.⁹ A programme tag connects a list record to relevant programme context, but it does not replace the underlying regulations, facts or authorisations.¹⁰ See types of sanctions and related restrictions for the wider comparison of blocking, rejection, asset freezes and non-list-based measures.

From an SDN List result to a sanctions decision

OFAC advises organisations investigating a potential match to identify the relevant list and programme, compare the complete entry and available identifiers, obtain more information where needed and apply their own sanctions procedures.¹¹ See the practical sanctions-screening guide for the wider investigation and evidence workflow.

A candidate match is not a confirmed SDN identity

Names can be shared, transliterated, abbreviated or recorded incompletely. A candidate should be assessed using available identifiers such as date and place of birth, addresses, nationality, identification numbers and entity details.

Even a likely identity match does not decide what action is legally required. The relevant programme, regulations, jurisdictional facts, authorisations, exemptions and licences still need consideration. Screening software can support this work; it cannot replace that determination.

Listed SDN versus an entity owned by blocked persons

An entity can be treated as blocked under OFAC's 50 Percent Rule even when its name is absent from the SDN List. OFAC states that an entity owned directly or indirectly, individually or in aggregate, 50% or more by one or more blocked persons is itself considered blocked.¹²

This is an ownership-analysis route, not a name-match result. Ownership below 50%, or control without the specified ownership, does not solely on that basis make the entity automatically blocked under this OFAC rule. See sanctions ownership and control for the separate US, UK and EU concepts.

SDN does not mean every sanctioned person

The UK Sanctions List is the current UK source for designations.¹³ EU restrictive measures arise through EU legal acts and are enforced within the EU framework and Member States.¹⁴ See OFAC and OFSI implications for compliance teams.

A controlled OFAC screening process

What secondary sanctions mean for a UK or EU business

US secondary-sanctions exposure and a business's obligations under UK or EU law are separate questions. A UK company should not infer that every OFAC restriction automatically applies as UK law. UK Protection of Trading Interests guidance currently addresses specified extraterritorial US measures concerning Iran and Cuba; it is not a general answer to every secondary-sanctions programme.¹⁵

The EU Blocking Statute applies to EU operators and the third-country laws listed in its Annex, currently specified US measures concerning Cuba and Iran. It includes notification, non-compliance, recovery and authorisation mechanisms within its defined scope; it is not a UK rule or a universal conflict-resolution mechanism.¹⁶

Where a live transaction, termination, licence or contractual decision creates potentially conflicting cross-border requirements, establish each applicable legal perimeter and obtain specialist advice. See the UK sanctions-screening guide for the UK operating layer.

Can sanctions screening detect secondary-sanctions risk?

Screening can identify candidate records for supplied people, companies, known beneficial owners, counterparties and supported assets and preserve available source context. It cannot by itself establish whether goods, services, end use, sector, geography, transaction significance or legal nexus triggers a secondary-sanctions authority.

A practical process should:

1. establish which sanctions regimes and sources are relevant;
2. screen the appropriate supplied parties against current sources;
3. investigate candidates using available identifiers;
4. consider applicable ownership and control rules; and
5. escalate the evidence under the organisation's procedures for an authorised legal or compliance decision.

OFAC encourages organisations subject to US jurisdiction to use risk-based sanctions-compliance programmes appropriate to their circumstances. It does not prescribe one universal screening system or matching threshold.¹⁷

How Checklynx supports the screening workflow

Checklynx can screen supplied party data against selected sanctions sources, present candidate matches with available identity and source context, and support review, monitoring and evidence workflows.

Your organisation remains responsible for deciding which regimes apply, establishing and verifying relevant facts, assessing ownership and control, and determining whether blocking, rejection, licensing, reporting or another action is required. Checklynx does not make those legal decisions or guarantee sanctions compliance.

Explore Checklynx sanctions screening for repeatable candidate generation, review and evidence across selected OFAC and other sanctions sources.

Frequently asked questions

What does SDN stand for?

SDN stands for Specially Designated National. The plural commonly refers to parties on OFAC's Specially Designated Nationals and Blocked Persons List.

Is the SDN List the same as the OFAC or US sanctions list?

No. OFAC maintains the SDN List and separate non-SDN lists. Restrictions depend on the relevant list, programme and regulations.

Does OFAC publish an official list of sanctioned countries?

No. OFAC publishes current programme and list information, but it does not maintain one definitive list of countries with which US persons cannot do business. Programme scope and restrictions must be checked in the current official sources.

Which countries are sanctioned by OFAC?

The question cannot be answered safely with one binary roster. Some programmes are broad and geographically oriented, while others target selected people, entities, sectors or activities. Use OFAC's current programme index for the relevant country or region.

Does being located in a country with an OFAC programme mean a person or company is sanctioned?

No. Location, nationality, residence or incorporation alone does not establish sanctions status. The relevant programme, list record, activity, ownership and US nexus still need to be assessed.

Do all OFAC sanctions require transactions to be blocked?

No. Some programmes involve blocking, while others impose narrower prohibitions. OFAC also distinguishes blocking from transaction rejection; the applicable programme and facts determine the response.

Does an SDN search result confirm a sanctions match?

No. Fuzzy searches can return candidates. Identity should be assessed using the complete official record and available identifiers before legal effect is considered.

Is an unlisted company outside OFAC blocking rules?

Not necessarily. Under OFAC's 50 Percent Rule, specified ownership by blocked persons can make an unlisted entity itself blocked.

Are people on UK or EU sanctions lists called SDNs?

Not as a generic legal term. SDN is an OFAC/US concept. The UK and EU maintain distinct designation sources and legal frameworks.

Does OFAC require automated SDN screening software?

OFAC encourages risk-based compliance controls but does not prescribe one universal screening system. Organisations should design controls for their obligations and risk.

What are secondary sanctions?

Secondary sanctions are programme-specific measures that can expose certain non-US persons to US sanctions consequences for specified conduct without the same direct US nexus as a primary prohibition. They do not extend every OFAC rule worldwide and do not have one universal consequence.⁴

What is the difference between primary and secondary sanctions?

Direct or primary prohibitions apply through the relevant US jurisdiction and programme rules. Secondary-sanctions authorities create additional, programme-specific exposure for certain non-US persons and conduct. The distinction is explanatory rather than one uniform statutory test.⁴

Do US secondary sanctions apply to UK companies?

Potentially, depending on the specific US authority and facts. The company's separate obligations under UK law must also be assessed. Certain US Iran and Cuba measures interact with the UK's Protection of Trading Interests regime, but that regime is not a defence or answer for every US programme.¹⁵

Do secondary sanctions always mean SDN listing or asset blocking?

No. Official US and UK material recognises blocking, non-blocking and banking-related consequences, including correspondent-account restrictions. The applicable authority determines the possible consequence.⁴

Can sanctions screening determine secondary-sanctions exposure?

No. Screening can surface relevant candidate parties and source context. It cannot by itself resolve activity, goods, services, end use, sector, geography, transaction significance, applicable nexus or the final legal consequence.