Suspicious Activity Report.

In plain English

A Suspicious Activity Report is a form a bank files with the government when a customer's activity looks like it could involve money laundering, fraud, or other financial crime. It is required under anti-money-laundering law, and by rule the bank cannot tell the customer that a report was filed. A SAR is not proof of wrongdoing; it flags a pattern for investigators to review. Banks file millions each year, most of which lead nowhere, as part of a wide net.

01Why it matters

SARs are a core part of how the financial system polices crime, and understanding them demystifies why banks quietly monitor unusual account activity.

02The math, step by step

A customer suddenly moves many round-number deposits just under the reporting threshold. The bank files a Suspicious Activity Report so investigators can review the pattern, without telling the customer.

03What this is NOT