Glossary
What Is the SDN List? Specially Designated Nationals Explained
The SDN List is the U.S. Treasury's master sanctions list. What it is, who's on it, and what you're actually required to do. Sourced from OFAC's published FAQs.
The SDN List (formally the Specially Designated Nationals and Blocked Persons List ) is the primary sanctions list maintained by OFAC, the U.S. Treasury's Office of Foreign Assets Control. It names individuals, companies, vessels, and aircraft that U.S. persons are prohibited from doing business with, and whose property must be blocked (frozen) if it comes into U.S. possession or control.
TL;DR
What it is: A U.S. Treasury list of people and organizations subject to U.S. economic sanctions.
Who runs it: OFAC, part of the U.S. Department of the Treasury.
Legal effect: U.S. persons can't deal with anyone on the list; their property must be blocked and reported to OFAC within 10 business days.
Who it covers: Terrorists, narcotics traffickers, WMD proliferators, and individuals or companies linked to sanctioned regimes.
How often it changes: No fixed schedule. Names are added and removed as needed, sometimes several times a week.
Who ends up on the SDN List?
OFAC uses two categories, straight from its own FAQ language:
Country-program designations. Individuals and companies
"owned or controlled by, or acting for or on behalf of, targeted countries."
When the U.S. sanctions a regime (Iran, North Korea, Cuba, Syria, etc.), front companies and individuals tied to that regime end up here.
List-based (non-country) programs. Individuals and entities designated under authorities that aren't country-specific: terrorists under Executive Order 13224 (authorized under IEEPA), kingpins under the Foreign Narcotics Kingpin Designation Act, WMD proliferators, transnational criminal organizations, cyber actors, human rights abusers, and others.
Each SDN entry includes a program code (for example SDGT for Specially Designated Global Terrorist, IRAN, or NARCOTICS) identifying the statutory authority. Entries typically carry aliases, dates of birth, places of birth, passport numbers, tax IDs, vessel IMO numbers, and aircraft tail numbers.
What does being on the SDN List mean for a business?
Two obligations, both straight from OFAC's regulations:
- You can't deal with them
A U.S. person — and the definition is broader than "U.S. citizen," covering permanent residents, U.S.-organized companies and their foreign branches, and anyone physically present in the U.S. — is generally prohibited from any transaction with an SDN. Payments, contracts, exports, imports, services, anything of value. A handful of programs carve out exemptions (humanitarian goods, informational materials, personal communications), but the default is: no dealings without an OFAC license.
- You have to block their property
If property or interests in property of an SDN come into a U.S. person's possession or control, that property must be blocked — frozen in place. The owner keeps legal title, but no one can transfer, withdraw, or otherwise deal in the property without an OFAC license. Blocked property must be reported to OFAC within 10 business days of the property becoming blocked.
OFAC enforcement is strict-liability. You can be penalized even if you didn't know the counterparty was sanctioned. "I didn't screen" is not a defense.
SDN List vs Consolidated Sanctions List (the non-SDN lists)
This is where compliance teams get tripped up. OFAC maintains two different groupings:
SDN List. Full blocking and a general prohibition on dealings.
Consolidated Sanctions List (non-SDN lists). A set of secondary lists with narrower restrictions. They do not trigger full blocking unless the target is also on the SDN List. Examples:
SSI List (Sectoral Sanctions Identifications): Restricts specific transactions, such as certain debt and equity financing of sanctioned sectors.
FSE List (Foreign Sanctions Evaders): Non-U.S. persons determined to have violated or facilitated evasion of U.S. sanctions.
Other specialized lists, including the Non-SDN Palestinian Legislative Council list and the CAPTA list.
If you screen only the SDN List, you're covering the core blocking cases but missing the sectoral and secondary restrictions. A serious compliance program screens both.
How often is the SDN List updated?
OFAC's own answer, paraphrased from FAQ 20:
"The SDN List is frequently updated. There is no predetermined timetable, but rather names are added or removed as necessary and appropriate."
In practice:
Several updates in a single week during active designation campaigns (recent waves have included Russia-related designations, Venezuela, and Iran-linked IRGC actions).
- Occasional quiet stretches with no additions or removals.
Changes announced through OFAC's Recent Actions page and reflected in downloadable change-data files.
Checking a name once at onboarding and never again isn't a compliance program. OFAC expects continuous monitoring: re-screen customers and counterparties every time the SDN List changes.
How to access the SDN List
The list is free and public. OFAC publishes it at ofac.treasury.gov in several formats:
Human-readable (PDF, HTML) — for browsing, not machine integration.
XML — structured schema exposing aliases, addresses, DOBs, ID documents, vessel details, and linked programs.
Fixed-field / delimited files — legacy plain text formats that some older compliance systems still rely on.
Sanctions List Search tool — OFAC's web interface for one-off name lookups.
If you integrate directly, you'll write against OFAC's change-data files and wrestle with the XML schema and its quirks: nested aliases, multiple ID documents per entry, linked sanctions programs, and vessel / aircraft details. Most teams use a screening tool — that's what SanctScan does so your engineers can stop debugging XML parsers.
What to do if you get a potential SDN match
OFAC's own guidance (FAQ 23): if you find a match, don't act immediately. Is the name exact or close? Is your customer in roughly the same location as the listed person? If not, it's probably a false hit. If there are real similarities, call OFAC's compliance hotline before doing anything.
In practice:
Compare secondary identifiers (date of birth, nationality, address, ID numbers) before deciding whether the match is real.
Document the adjudication. Every match decision, even a false positive, belongs in an audit trail you can show a regulator.
If confirmed: block the transaction, report blocked property to OFAC within 10 business days, and consider whether voluntary self-disclosure is appropriate. Self-disclosure is a documented mitigating factor under OFAC's Economic Sanctions Enforcement Guidelines.
If you can't tell: call the
OFAC Compliance Hotline
. It's free.
The 50% Rule and the SDN List
If one or more SDNs own 50% or more of an entity, directly or indirectly (aggregated across all blocked owners), that entity is automatically blocked even if its name never appears on the SDN List.
In other words, screening just the names on the list isn't enough. You also need beneficial-ownership data to catch entities blocked under the 50% Rule.
Screen the SDN List with SanctScan
We built SanctScan so compliance teams don't have to parse OFAC's XML or write their own fuzzy matcher. The free OFAC SDN check gives you instant lookups with transliteration-aware fuzzy matching, useful for one-off checks where Treasury's exact-match search falls short.
For continuous monitoring, the API, and audit-ready logs, see SanctScan's OFAC screening software or the broader guide to OFAC screening .
Frequently asked questions
- What does "SDN" stand for?
- "Specially Designated Nationals and Blocked Persons." It is the full name of the list; "SDN List" is the standard shorthand used by OFAC and by the compliance industry.
- Is the SDN List the same as the OFAC list?
- Not exactly. The SDN List is OFAC's largest list and what most people mean when they say "the OFAC list." But OFAC also maintains the Consolidated Sanctions List (non-SDN lists like SSI and FSE) and several others. A complete compliance program screens all of them.
- Who has to screen against the SDN List?
- All U.S. persons — U.S. citizens, permanent residents, U.S.-incorporated companies (including their foreign branches), and anyone physically present in the United States. Non-U.S. persons are also exposed if their transactions involve U.S. persons, U.S. dollars, U.S. territory, or U.S.-origin goods. Banks, fintechs, crypto exchanges, law firms, and any business with international counterparties screen routinely.
- How many people and entities are on the SDN List?
- Tens of thousands of entries covering individuals, companies, vessels, and aircraft. The count changes constantly. Any specific number goes stale quickly, so use OFAC's data files for a current count.
- What happens if I deal with an SDN by mistake?
- OFAC enforcement is generally strict-liability, which means you can be penalized even if you did not know the counterparty was sanctioned. Civil penalties are adjusted annually for inflation under the Federal Civil Penalties Inflation Adjustment Act. Voluntary self-disclosure, a credible compliance program at the time of the violation, and cooperation are mitigating factors under OFAC's Economic Sanctions Enforcement Guidelines.
- How often does OFAC update the SDN List?
- OFAC's official answer (FAQ 20): the list is "frequently updated" with no predetermined timetable. Names are added and removed "as necessary and appropriate." In practice, updates can come several times a week during active campaigns, or go quiet for a week or two.
- Where can I search the SDN List for free?
- Treasury runs its own Sanctions List Search tool at sanctionssearch.ofac.treasury.gov. SanctScan also offers a free OFAC SDN check with fuzzy matching that handles spelling and transliteration variations, with no signup required.
- What's the difference between the SDN List and the Consolidated Sanctions List?
- The SDN List requires full blocking: you cannot deal with listed persons at all, and their property must be frozen. The Consolidated Sanctions List (non-SDN lists such as SSI, FSE, and others) imposes narrower prohibitions on specific kinds of transactions but does not trigger full blocking unless the target is also on the SDN List. A thorough compliance program screens both.
Primary sources
This page paraphrases and quotes OFAC's published guidance. Direct references: