Do transactions just below $10,000 automatically require a SAR?

No. Transactions at or near the $10,000 CTR threshold do not automatically require a SAR, but being under $10,000 is not a safe harbor either.

What the guidance says:

• The mere presence of a transaction or series of transactions by or on behalf of the same person at or near the $10,000 CTR threshold is not information sufficient to require a SAR. This applies across the institution types covered by the SAR rules, including MSBs and banks (FinCEN SAR FAQs, Oct. 9, 2025, Question 1).
• For potential structuring, a SAR is required only if the institution knows, suspects, or has reason to suspect that the transactions are designed to evade CTR reporting requirements, and the other conditions of its SAR rule, such as its dollar threshold, are met (FinCEN SAR FAQs, Question 1).

What the rule says about structuring:

• "In any manner" includes, but is not limited to, breaking down a single sum of currency exceeding $10,000 into smaller sums, including sums at or below $10,000, or conducting a transaction or series of currency transactions at or below $10,000 (31 CFR 1010.100(xx)).
• Structuring covers one or more currency transactions, in any amount, at one or more financial institutions, on one or more days, for the purpose of evading the reporting requirements. The transactions need not exceed $10,000 at any single institution on any single day (31 CFR 1010.100(xx)).
• No person may structure, assist in structuring, or attempt either, with one or more domestic financial institutions. That applies to customers, not just institutions (31 CFR 1010.314(c)).

What to do:

• Keep structuring in your monitoring. The FAQs say an AML/CFT program should be designed to detect and report structuring, with monitoring commensurate with the institution's money laundering and terrorist financing risk, considering its products and services, locations served, and customers (FinCEN SAR FAQs, Question 1).
• When reviewing an alert, look at whether anything indicates the activity was designed to evade CTR reporting, such as breaking up a larger sum or repeated currency activity at or below $10,000 by or on behalf of the same person.
• If you know, suspect, or have reason to suspect evasion and your SAR dollar threshold is met, a SAR is required.

Threshold check: for banks, the SAR rule applies to transactions involving or aggregating at least $5,000 (31 CFR 1020.320(a)(2)). MSBs and other institution types should confirm the dollar threshold in their own SAR rule.

Sources

1. FinCEN SAR FAQs (Oct. 9, 2025), Question 1: https://www.fincen.gov/system/files/2025-10/SAR-FAQs-October-2025.pdf
2. 31 CFR §§ 1010.314(a)-(c), 1010.100(xx): https://www.law.cornell.edu/cfr/text/31/1010.100

This answer is general information, not legal advice. Forteris is not a law firm.