SAR vs CTR: Suspicious Activity Reports vs Currency Transaction Reports
Two different filing obligations, triggered by two different things - founders often confuse or conflate them.
If your business is subject to AML/BSA obligations (typically once MSB status or similar applies), you may need to file two different types of reports with FinCEN: Suspicious Activity Reports (SARs) and Currency Transaction Reports (CTRs). They're triggered by different things and serve different purposes.
Currency Transaction Report (CTR)
Filed for cash transactions above a specific federal threshold, regardless of whether anything about the transaction looks suspicious. A CTR is a routine, volume-based filing - it doesn't imply wrongdoing, it's simply required once a transaction crosses the threshold. Confirm the current threshold with FinCEN's published guidance, since it can be adjusted.
Suspicious Activity Report (SAR)
Filed when a transaction or pattern of activity appears suspicious, regardless of dollar amount - this is judgment-based, not threshold-based. Common triggers include transactions that don't match a customer's known profile, structuring (breaking transactions into smaller amounts to avoid CTR thresholds), or activity consistent with known fraud or money-laundering patterns. SARs are confidential - the subject of a SAR is not notified that one was filed, and disclosing that a SAR was filed is itself a violation.
Why founders mix these up
Both are FinCEN filings and both come up in the same compliance conversations, which makes it easy to assume they're two versions of the same thing. They aren't: CTR is about a dollar threshold, SAR is about a judgment call on suspicious activity. Some situations require both.
What this means operationally
Your AML program needs to actually monitor for both triggers separately - a system built only to catch large transactions (for CTR) won't necessarily catch a suspicious pattern of smaller ones (which might warrant a SAR). This is part of why a generic AML template often falls short for a specific business's actual transaction patterns.
Next step
If you're not sure whether your current AML setup actually monitors for both SAR and CTR triggers, that's worth confirming as part of a broader framework review.
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Related reading: AML/KYC Readiness Checklist for a US Launch · How to Pass an AML Audit · MSB Eligibility Guide