FinCEN's 2019 advisory (FIN-2019-A003) outlined seven categories of crypto-specific information essential for Suspicious Activity Reports (SARs). Seven years later, financial institutions still struggle to surface this data efficiently. Unlike fiat, blockchain provides a permanent public ledger, but extracting relevant details for a crypto SAR requires specific expertise. In the US, SARs must be filed within 30 days of detection ($5,000+ threshold with suspects, $25,000+ without). The narrative should include wallet addresses, transaction hashes, IP addresses, and other data, while explaining red flags and deviations from normal patterns. FinCEN's April 2026 proposed rule shifts focus from technical compliance to effectiveness, emphasizing useful reporting. Common pitfalls include overfiling without explanation, vague narratives, and failing to supplement filings. Blockchain analytics tools like Elliptic Lens help reduce false positives, speed up alert resolution, and automatically generate SAR narratives, cutting preparation time by up to 55%. Quality filings enable law enforcement to trace funds, connect cases, and identify victims.

Key facts

• FinCEN advisory FIN-2019-A003 lists seven crypto-specific data points for SARs.
• US SARs must be filed within 30 days; thresholds: $5,000 (suspects) or $25,000 (no suspects).
• Effective narratives include wallet addresses, hashes, IPs, and explain red flags.
• FinCEN’s 2026 proposed rule emphasizes effectiveness over check-the-box compliance.
• Blockchain analytics tools can reduce false positives and cut SAR prep time by 55%.