Understanding the OFAC SDN List

What Is the SDN List?

The Specially Designated Nationals and Blocked Persons List, commonly called the SDN List, is the primary sanctions list maintained by OFAC. It contains the names of individuals, companies, vessels, and other entities that US persons are prohibited from doing business with. If someone is on the SDN List, their assets under US jurisdiction must be blocked, and US persons cannot engage in transactions with them.

What Types of Entries Are on the SDN List?

The SDN List includes several types of entries:

• Individuals: People designated under various sanctions programs, including terrorists, narcotics traffickers, and government officials of sanctioned regimes.
• Entities: Companies, organizations, and other groups that have been designated.
• Vessels: Ships and aircraft associated with sanctioned parties.
• Aliases: Many entries include alternate names, spellings, and transliterations. A single person might have five or more aliases listed.

Each entry includes identifying information such as dates of birth, nationalities, passport numbers, addresses, and other details that help with identification. The level of detail varies. Some entries are thorough; others have minimal information.

How Often Is the SDN List Updated?

OFAC updates the SDN List frequently, sometimes multiple times per week. There is no fixed schedule. Updates can include new designations, removals, and changes to existing entries. This is why one-time screening is not enough. You need to rescreen your existing customers and counterparties on a regular basis to catch new additions.

OFACScreen updates its copy of the SDN List automatically, so you are always screening against the most current data.

How Big Is the SDN List?

As of early 2025, the SDN List contains roughly 18,000 to 19,000 entries. When you factor in aliases and alternate spellings, the number of names you need to screen against is significantly higher. This is one reason why manual screening is impractical for most businesses.

What to Do If You Get a Match

Getting a hit against the SDN List does not necessarily mean you have found a sanctioned party. Many matches are false positives, especially with common names. Here is what to do:

1. Do not panic. A potential match is not a confirmed match until you verify it.
2. Review the identifying details. Compare the match against all available information: date of birth, address, nationality, ID numbers. The more data points that align, the more likely it is a true match.
3. If it is a false positive, document your review and the reasons you determined it was not a true match. Keep this on file.
4. If it appears to be a true match, block the transaction immediately. Do not process it, and do not tip off the customer. File a blocking report with OFAC within 10 business days.
5. Consult legal counsel if you are unsure. When in doubt, err on the side of caution.

False Positives Are Normal

False positives are a routine part of sanctions screening. Common names like "Mohammed Ali" or "John Smith" will generate matches regularly. The key is having a clear process for reviewing and documenting each one. Good screening software helps by providing enough context, such as identifying details and match scores, to make the review process efficient.

OFACScreen flags potential matches with a similarity score and displays the relevant identifying details side by side, so your compliance team can quickly determine whether a match is real or a false positive.