OFAC Sanctions Screening for Trading Platforms

Updated Dec 2025 22 min read Critical Compliance

OFAC Overview & Authority

The Office of Foreign Assets Control (OFAC) is a division of the U.S. Department of the Treasury that administers and enforces economic and trade sanctions based on U.S. foreign policy and national security goals. For trading platforms and financial institutions, OFAC compliance is not optional—it's a federal legal requirement with severe civil and criminal penalties for violations.

OFAC operates under presidential national emergency powers and specific legislation to impose controls on transactions and freeze assets under U.S. jurisdiction. Sanctions can be country-based (comprehensive sanctions against entire countries) or list-based (targeting specific individuals, entities, vessels, and aircraft).

Strict Liability Standard

OFAC violations are subject to strict liability. This means you can be penalized even if the violation was unintentional or you had no knowledge that a transaction involved a sanctioned party. Lack of awareness is not a defense. This makes robust screening and due diligence essential.

OFAC's Legal Authority

OFAC derives its authority from several key statutes:

Who Must Comply?

OFAC regulations apply to all U.S. persons—including citizens, permanent residents, entities organized under U.S. law, and any person within the United States—as well as foreign entities owned or controlled by U.S. persons. If your trading platform serves U.S. customers or operates in U.S. jurisdiction, you must comply with OFAC sanctions.

Sanctions Programs & Lists Overview

OFAC maintains multiple sanctions programs and publishes several lists that financial institutions must screen against. Understanding the differences between these lists and programs is critical for effective compliance.

Types of Sanctions Programs

Program Type Description Examples
Comprehensive Sanctions Broad prohibitions on virtually all transactions with a target country Cuba, Iran, North Korea, Syria, certain regions of Russia/Ukraine
List-Based Sanctions Target specific individuals, entities, and vessels regardless of location SDN List, Sectoral Sanctions Identifications (SSI) List
Sectoral Sanctions Prohibit specific types of transactions with designated entities in certain sectors Russia energy, financial, and defense sectors
Secondary Sanctions Target non-U.S. persons for activities with sanctioned jurisdictions Iran-related secondary sanctions, Russia-related measures

OFAC Lists Comparison

Primary OFAC Sanctions Lists

List Name Entries Prohibition Update Frequency
SDN List
Specially Designated Nationals and Blocked Persons
~11,000+ All transactions prohibited; assets must be blocked Weekly or more
SSI List
Sectoral Sanctions Identifications
~300+ Limited prohibitions based on directive (e.g., debt financing over 90 days) As needed
FSE List
Foreign Sanctions Evaders
~90 All transactions prohibited As needed
Non-SDN Menu-Based
Menu-based sanctions entities
Varies Certain sanctions apply (varies by program) As needed
CMIC List
Chinese Military-Industrial Complex
~60 Prohibition on securities transactions by U.S. persons Periodic updates

SDN List Screening Requirements

The Specially Designated Nationals and Blocked Persons List (SDN List) is OFAC's primary sanctions list. It identifies individuals, entities, vessels, and aircraft whose property and interests in property are blocked under U.S. sanctions programs. U.S. persons are generally prohibited from dealing with SDNs.

SDN List Contents

The SDN List includes comprehensive identifying information:

SDN List Sources and Updates

Trading platforms must access the most current SDN List data:

Official Sources
  • OFAC website (treasury.gov/ofac)
  • SDN List downloadable files (TXT, CSV, XML, PDF)
  • Consolidated Sanctions List (all OFAC lists combined)
  • Sanctions List Search tool (online lookup)
Update Frequency
  • Updates posted irregularly (often weekly)
  • Breaking sanctions may be announced suddenly
  • Email notification service available
  • RSS feed for automated monitoring
Data Formats
  • Pipe-delimited TXT file (legacy)
  • CSV format (structured data)
  • XML format (machine-readable)
  • PDF format (human-readable)
Integration Methods
  • Automated daily downloads
  • Third-party screening vendor integration
  • API-based screening services
  • Real-time web service queries

List Update Timing

OFAC can add new entries to the SDN List at any time, often with little or no advance notice. Major geopolitical events can trigger sudden sanctions designations affecting hundreds of entities. Your screening system must update lists at least daily, and you should monitor OFAC announcements for breaking sanctions that require immediate action.

The 50 Percent Rule

One of the most critical—and frequently misunderstood—aspects of OFAC compliance is the "50 Percent Rule." This rule significantly expands the scope of blocked persons beyond those explicitly listed on the SDN List.

50 Percent Rule Explained

OFAC's 50 Percent Rule states that entities owned 50% or more, directly or indirectly, by one or more SDNs are themselves considered blocked persons, even if they are not explicitly included on the SDN List. This applies regardless of whether the ownership is held by a single SDN or multiple SDNs in the aggregate.

Automatic Blocking Without Listing

Under the 50 Percent Rule, an entity can be blocked even though it does not appear on any OFAC list. U.S. persons must conduct their own analysis of ownership structures to identify blocked entities. This creates significant due diligence obligations, particularly for complex corporate structures.

50 Percent Rule Application

Scenario Ownership Structure Blocked Status
Direct Majority Ownership SDN owns 50% or more of Entity A Entity A is blocked
Multiple SDN Ownership SDN 1 owns 30%, SDN 2 owns 25% of Entity B Entity B is blocked (55% aggregate SDN ownership)
Indirect Ownership SDN owns 100% of Entity C; Entity C owns 60% of Entity D Both Entity C and Entity D are blocked
Layered Ownership SDN owns 80% of Entity E; Entity E owns 80% of Entity F Both Entity E (80% SDN-owned) and Entity F (64% indirect SDN ownership) are blocked
Below Threshold SDN owns 49% of Entity G Entity G is NOT automatically blocked (but enhanced due diligence recommended)

Compliance Implications

The 50 Percent Rule requires trading platforms to:

Practical Challenges

The 50 Percent Rule creates substantial compliance challenges. Ownership structures can be complex, opaque, and change frequently. Many jurisdictions do not require public disclosure of beneficial ownership. For high-risk customers or jurisdictions, enhanced due diligence including independent verification of ownership may be necessary. Consider contractual representations and periodic re-certification of ownership structures.

Screening Frequency Requirements

Effective OFAC compliance requires screening at multiple points in the customer lifecycle and transaction flow. A risk-based approach determines the appropriate frequency and depth of screening.

When to Screen

1. Onboarding Screening
  • Screen before account opening
  • Check individual names and entity names
  • Verify beneficial owners (50% rule)
  • Screen addresses and nationalities
  • Block account if match confirmed
2. Transaction Screening
  • Real-time screening of payments
  • Screen all transaction parties
  • Check originators and beneficiaries
  • Review payment instructions/references
  • Interdiction before processing
3. Ongoing Monitoring
  • Daily or weekly batch re-screening
  • Re-screen when SDN List updates
  • Quarterly or annual customer review
  • Monitor for ownership changes
  • Continuous geographic screening
4. Event-Triggered Screening
  • Customer name or address changes
  • New beneficial owner disclosed
  • New sanctions program announced
  • Geopolitical developments
  • Unusual transaction patterns

Screening Frequency Best Practices

Screening Type Minimum Frequency Higher-Risk Frequency Rationale
Customer Onboarding Before account approval Real-time during application Prevent SDN accounts from opening
Transaction Processing Real-time for all transactions Enhanced screening for high-value/cross-border Prevent prohibited transactions
Customer Database Screening Weekly against updated lists Daily or upon each list update Identify newly-designated SDNs in existing customer base
Beneficial Ownership Review Annually for entity accounts Quarterly or upon material events Detect ownership changes triggering 50% rule
Geographic Risk Screening Continuous IP/location monitoring Enhanced for VPN/proxy detection Block access from sanctioned jurisdictions

Automated Re-Screening

Leading trading platforms implement automated batch re-screening that runs whenever OFAC updates its sanctions lists. When new SDNs are designated, the system immediately screens all existing customers and accounts against the new entries, generating alerts for review. This approach ensures rapid detection of newly-sanctioned parties and minimizes exposure.

Screening Workflow & Name Matching

Effective OFAC screening requires sophisticated name-matching technology and well-defined investigation workflows. Simple exact-match searches are insufficient given name variations, transliterations, and data quality issues.

Name Matching Techniques

Technique Description Use Case Pros/Cons
Exact Match Character-for-character identical match Initial filter; high-confidence hits Fast, no false positives; misses variations
Fuzzy Matching Allows for variations using Levenshtein distance or similar algorithms Primary screening method Catches misspellings; generates false positives
Phonetic Matching Matches names that sound similar (Soundex, Metaphone) Transliterations from other alphabets Handles pronunciation variations; language-dependent
Nickname/Alias Matching Database of known aliases and name variants Individuals using multiple names Comprehensive; requires database maintenance
Weak Alias Matching Broader matching for low-quality OFAC aliases When OFAC lists uncertain names Catches edge cases; very high false positives

Common Screening Challenges

Screening Workflow

OFAC Screening & Investigation Workflow

1Automated Screening

System screens customer/transaction data against OFAC lists using fuzzy logic; generates alerts for potential matches

2Alert Queue & Prioritization

Alerts sorted by match score/confidence; high-confidence matches escalated immediately; lower-confidence matches queued for review

3Level 1 Investigation

Analyst compares customer data to SDN entry; reviews name, address, DOB, ID numbers, nationality; determines if match is possible

4Enhanced Investigation (if needed)

For unclear cases, gather additional information; review supporting documentation; check additional identifiers; research entity relationships

5Decision & Action

Determine: True Match (block/reject) or False Positive (clear/process); document decision rationale; escalate uncertain cases

6Execution & Reporting

True Match: Block assets, file OFAC report; False Positive: Clear alert, process transaction; maintain audit trail of decision

False Positive Resolution Procedures

Aggressive fuzzy matching generates high false positive rates—often 95%+ of initial matches are false positives. Efficient false positive resolution is critical to operational effectiveness while maintaining compliance integrity.

False Positive Investigation Framework

Analysts should systematically compare identifying information:

False Positive Analysis Checklist

  • Compare full name against SDN name and all aliases
  • Check if customer address matches or is near SDN address
  • Compare date of birth (if available) with SDN date of birth
  • Verify nationality against SDN nationality or citizenship
  • Check ID numbers (passport, national ID, tax ID) against SDN identifiers
  • Review customer occupation/business vs. SDN description
  • For entities, compare corporate registration details
  • Assess whether additional context makes match plausible
  • Consider whether customer could be using alias or false identity
  • Document specific reasons for clearing as false positive
  • Escalate uncertain cases to senior compliance officer
  • Maintain audit trail of investigation and decision

Match Quality Factors

Factor Strong Match Indicator Weak Match Indicator
Name Match Exact match or very close variation Common name, different middle name or spelling
Address Same city and country, or close proximity Different country or distant location
Date of Birth Exact match or within 1-2 years Significantly different age or no DOB for SDN
Nationality Same citizenship or strong connection Completely different nationality with no connection
Identifiers Matching passport, ID, or registration number Different ID numbers
Context Business type, occupation, or associates align Implausible that customer could be SDN

Common Name Problem

Common names generate disproportionate false positives. For example, "Mohammed Ali" or "John Smith" may match thousands of individuals who are not the sanctioned person.

Common Name Screening Strategy

For very common names, implement additional verification steps: collect and verify date of birth, full address, nationality, and identification documents. Consider secondary identifiers such as email addresses, phone numbers, or IP geolocation. Document your rationale for clearing common name matches and consider enhanced monitoring for these accounts.

Documentation Requirements

For every screening alert (whether true or false positive), maintain:

Blocking Procedures When Hits Occur

When screening identifies a confirmed or likely SDN match, you must take immediate action to block the property and interests in property of the SDN. Blocking means prohibiting any transaction or dealing and freezing assets under your control.

Rejection vs. Blocking

It's critical to distinguish between rejection and blocking:

Action When Required Procedure Reporting
Rejection Transaction involves sanctioned country but no SDN property interest Refuse/reject the transaction; do not process No blocking report to OFAC (maintain internal records)
Blocking Property or property interest of an SDN Freeze assets, prohibit all dealings, segregate funds File blocking report with OFAC within 10 business days

What Must Be Blocked

Under OFAC regulations, you must block all property and interests in property of SDNs. This includes:

Blocking Procedures Timeline

Immediate (Day 0)
Block all assets: Freeze account, halt all transactions, prevent any withdrawals or dealings, segregate funds in internal systems
Within 24 hours
Internal notification: Notify senior management, legal, and compliance; document circumstances of blocking; secure all records
Within 10 business days
File blocking report: Submit initial blocking report to OFAC with all required information and supporting documentation
Ongoing
Maintain blocked status: Assets remain blocked indefinitely until OFAC authorizes release; do not unblock without OFAC license
Annually (by Sept 30)
Annual report: Submit annual report of blocked property held as of June 30 each year

No Delay Permitted

Blocking must occur immediately upon identifying an SDN match—do not wait for further investigation or the 10-day reporting deadline. Even a few hours of delay in blocking can constitute a violation. Implement automated account freezing capabilities that can execute instantly upon compliance approval.

Blocking Notification to Customer

You may need to notify the customer that their assets have been blocked, but must be careful not to "tip off" or assist sanctions evasion:

Reporting Requirements to OFAC

When you block property of an SDN, you must report the blocking to OFAC within specific timeframes. There are several types of OFAC reports trading platforms may need to file.

Initial Blocking Report (Within 10 Business Days)

Required information for initial blocking reports:

Annual Report of Blocked Property (Due September 30)

All financial institutions holding blocked property must file an annual report by September 30 each year reporting blocked assets held as of June 30. This report updates OFAC on all blocked property in your custody.

Rejected Transaction Records

While no formal report to OFAC is required for rejected transactions (those involving sanctioned countries but no SDN property interest), you must maintain detailed internal records:

Filing Methods

OFAC blocking reports should be submitted:

Unblocking Requires OFAC Authorization

Once property is blocked, you may not unblock or release it without specific authorization from OFAC, even if you later determine the blocking was in error. If you believe blocking was erroneous, you must seek an OFAC license to unblock. Never unblock property on your own determination without OFAC approval.

License Application Process

In certain circumstances, you or your customer may need to request a license from OFAC to engage in a transaction that would otherwise be prohibited. OFAC issues two types of licenses: general licenses (pre-authorized categories) and specific licenses (individual applications).

General Licenses vs. Specific Licenses

License Type Description Application Required? Examples
General License Pre-authorized categories of transactions published in sanctions regulations No application; can rely if transaction fits published criteria Humanitarian aid, informational materials, personal remittances (if authorized)
Specific License Individual authorization for a specific transaction or set of transactions Yes; must submit detailed application and await written approval Unblocking mistakenly blocked funds, legal fee payments, wind-down activities

When to Seek a Specific License

Common scenarios requiring specific license applications:

Specific License Application Process

OFAC Specific License Application Workflow

1Confirm No General License Applies

Review published general licenses in relevant sanctions program regulations; if none authorizes your transaction, proceed with specific license application

2Gather Required Documentation

Collect: detailed transaction description, parties involved, amounts, justification, supporting documents, proposed compliance measures

3Submit Application

Use OFAC's online licensing portal or submit by mail/email; include all required information and attachments; request expedited review if urgent

4OFAC Review Period

OFAC reviews application; may request additional information; typical review time 90-180 days but can be longer; no transaction permitted during review

5Receive Decision

OFAC issues: written approval (may include conditions), denial, or return without action; if approved, comply with all license terms and conditions

No Presumption of Approval

Submitting a license application does not authorize you to proceed with the transaction while awaiting OFAC's decision. The transaction remains prohibited until and unless OFAC grants a specific license in writing. Plan for potentially lengthy review periods and have no expectation of approval.

Third-Party Screening Tools Comparison

Most trading platforms implement OFAC screening through third-party software vendors rather than building proprietary solutions. Selecting the right screening tool is critical to compliance effectiveness and operational efficiency.

Leading OFAC Screening Solutions

Dow Jones Risk & Compliance
Comprehensive watchlist screening, fuzzy matching, API integration, real-time updates, case management. Strong name-matching algorithms and global coverage.
Pricing: Enterprise (contact for quote); typically $10K-50K+ annually depending on volume
Refinitiv World-Check
Market-leading watchlist database, PEP screening, adverse media, ongoing monitoring. Extensive coverage and regular updates. Strong for large financial institutions.
Pricing: Enterprise (contact for quote); typically $15K-100K+ annually
ComplyAdvantage
AI-powered screening, real-time watchlist updates, automated monitoring, crypto transaction screening. Modern API-first architecture suitable for fintech.
Pricing: Starts around $12K annually; scales with volume and features
Chainalysis KYT (Know Your Transaction)
Specialized for cryptocurrency platforms. Real-time transaction monitoring, wallet screening, sanctions compliance for digital assets. Integrates blockchain analytics.
Pricing: Enterprise (contact for quote); typically $25K-100K+ annually
Elliptic
Crypto-focused compliance platform. Wallet screening, transaction monitoring, OFAC sanctions compliance for virtual currencies. Strong blockchain analytics capabilities.
Pricing: Contact for quote; competitive with Chainalysis
Sanctions.io
Lightweight API-based screening service. Simple integration, real-time OFAC list updates, basic fuzzy matching. Good for smaller platforms or supplemental screening.
Pricing: Usage-based; ~$0.01-0.05 per check; free tier available
OFAC Sanctions Search (Official)
OFAC's own web-based search tool. Free, authoritative source, but manual searches only. No API or bulk screening. Useful for verification and ad-hoc lookups.
Pricing: Free

Selection Criteria for Screening Tools

When evaluating OFAC screening vendors, consider:

Dual-Vendor Strategy

Some high-risk or high-volume platforms implement dual screening vendors for critical transactions or onboarding. Running parallel screens through two independent systems provides additional assurance and can catch matches that one system might miss. While more expensive, this approach significantly reduces risk for platforms with substantial sanctions exposure.

OFAC Compliance Implementation Checklist

Use this comprehensive checklist to implement or enhance your OFAC sanctions screening program.

Complete OFAC Compliance Checklist

  • Designate a Sanctions Compliance Officer with authority and resources
  • Conduct written OFAC risk assessment specific to your trading platform
  • Develop comprehensive written OFAC compliance policies and procedures
  • Implement automated OFAC screening software with API integration
  • Screen all customers at onboarding against SDN and other OFAC lists
  • Screen all transactions in real-time or near-real-time before processing
  • Configure fuzzy logic and name-matching algorithms with appropriate thresholds
  • Establish written procedures for investigating and resolving screening alerts
  • Implement 50% ownership rule analysis for entity customers
  • Collect and verify beneficial ownership information (minimum 25%, recommend 50%)
  • Implement IP geolocation and geographic blocking for sanctioned countries
  • Collect and verify customer address and nationality information
  • Subscribe to OFAC list updates and re-screen customers when lists change
  • Develop written procedures for blocking assets and reporting to OFAC
  • Create alert escalation procedures for potential SDN matches
  • Establish 10-day blocking report timeline and procedures
  • Train all relevant personnel on OFAC requirements annually
  • Maintain comprehensive audit trail of all screening and decisions
  • Document false positive determinations with clear rationale
  • Conduct independent testing or audit of OFAC controls annually
  • Monitor OFAC guidance, general licenses, and sanctions program updates
  • Include OFAC compliance representations in customer agreements
  • Develop procedures for license applications when needed
  • Establish recordkeeping systems for rejected and blocked transactions (5 years)
  • Prepare incident response plan for potential violations and voluntary self-disclosure
  • For crypto platforms: implement wallet screening and blockchain analytics
  • Establish management reporting on OFAC screening metrics and issues
  • Review and update OFAC program at least annually or when material changes occur

Next Steps

Begin by conducting an OFAC risk assessment tailored to your trading platform's specific products, customers, and geographic footprint. Based on your risk profile, select appropriate screening technology, develop detailed written procedures, and train your team. OFAC compliance is an ongoing commitment requiring continuous monitoring, testing, and enhancement as sanctions programs evolve.

Disclaimer: This guide provides general educational information about OFAC sanctions screening requirements. It is not legal advice and does not create an attorney-client relationship. OFAC regulations are complex, change frequently, and carry severe civil and criminal penalties for violations. Consult with qualified sanctions counsel to develop a compliant OFAC screening program tailored to your specific business model, risk profile, and operational requirements.