OFAC Sanctions Screening for Crypto Wallets

Why OFAC screening matters for crypto businesses

The Office of Foreign Assets Control (OFAC) maintains the Specially Designated Nationals (SDN) list — a registry of individuals, entities, and blockchain addresses sanctioned by the US government. Any US person or business that transacts with a sanctioned address faces severe civil and criminal penalties.

Since 2022, OFAC has aggressively added blockchain addresses to the SDN list, including addresses associated with Tornado Cash, Lazarus Group, and other sanctioned entities. If your platform touches crypto, you need automated sanctions screening.

How WalletScreen handles OFAC screening

Automatic SDN list ingestion

WalletScreen fetches the full SDN list directly from the US Treasury's XML feed on startup and refreshes it every 6 hours. No manual updates, no stale data. When OFAC adds a new address, your next scan picks it up automatically.

Instant match, instant score

Any wallet address found on the SDN list or in our known exploiter registry is immediately assigned a risk score of 100 (maximum) with the label OFAC_SANCTIONED or KNOWN_EXPLOITER. There's no ambiguity — sanctioned means blocked.

Counterparty exposure detection

WalletScreen doesn't just check the wallet you're screening — it analyzes the wallet's transaction history and flags any interactions with sanctioned or exploiter addresses. A wallet that has sent funds to a Tornado Cash address will be flagged even if the wallet itself isn't on the SDN list.

curl https://walletscreener.io/wallet/0x8589427373D6D84E98730D7795D8f6f8731FDA16?chain=ethereum \
  -H "X-API-Key: ws_your_key_here"

{
  "address": "0x8589427373D6D84E98730D7795D8f6f8731FDA16",
  "risk_score": 100,
  "risk_label": "critical",
  "labels": ["OFAC_SANCTIONED"],
  "flagged_interactions": [...]
}

Beyond OFAC: layered risk intelligence

Sanctions screening is necessary but not sufficient. WalletScreen layers multiple risk signals on top of OFAC checks:

• Behavioral analysis — detect mixing patterns, rapid fan-out/fan-in, round-trip transfers
• Token forensics — flag wallets holding known scam tokens or high meme token exposure
• Cross-chain correlation — scan the same address across Ethereum, Polygon, Arbitrum, Base, Optimism, and zkSync simultaneously
• Continuous monitoring — webhook and email alerts when a monitored wallet's risk profile changes

Learn more about the full scoring methodology on our Wallet Risk Scoring API page.

Compliance use cases

Exchange deposit screening

Screen every incoming deposit address before crediting funds. If the source wallet is sanctioned or high-risk, hold the deposit for compliance review. WalletScreen's sub-second response time means screening happens inline — no delays for your users.

Withdrawal gating

Before processing a withdrawal to an external address, verify the destination isn't sanctioned. This protects your platform from facilitating transactions with blocked entities.

Periodic portfolio audits

Use the batch endpoint to screen your entire user base periodically. The SDN list changes — an address that was clean last month may be sanctioned today. Batch screening up to 100 wallets per call makes this practical at scale.

Audit trail & reporting

Every scan is stored in WalletScreen's history. Generate PDF reports for any scan to include in your compliance records. Regulators expect documentation — WalletScreen provides it automatically.

Regulatory landscape

OFAC screening requirements apply to:

• Money Services Businesses (MSBs) registered with FinCEN
• Virtual Asset Service Providers (VASPs) under FATF guidance
• Banks and neobanks offering crypto on/off-ramps
• DeFi protocols with US-facing interfaces (per recent OFAC guidance)
• Payment processors handling crypto-to-fiat conversions

Even if your business is outside the US, transacting with US persons or using US-dollar stablecoins can trigger OFAC obligations.