Enigma Knowledge

Glossary

SAR: Suspicious Activity Report

February 5, 2026

What a Suspicious Activity Report is, when to file one, and how SARs relate to KYB compliance.

A Suspicious Activity Report (SAR) is a filing with FinCEN when a financial institution detects activity that may indicate money laundering, terrorist financing, fraud, or other financial crimes.

When to File a SAR

SARs are required under the Bank Secrecy Act when:

  • Transactions of $5,000 or more involve suspected illegal activity
  • Any amount if terrorism is suspected
  • Activity indicates potential violations of law

What SARs Contain

  • Description of the suspicious activity
  • Parties involved (subject information)
  • Financial instruments used
  • Why the activity is considered suspicious
  • Supporting documentation references

SAR Confidentiality

Critical: SARs are confidential.

  • Institutions cannot disclose to the customer that a SAR was filed
  • Discussing SAR filings with the subject is prohibited ("tipping off")
  • SAR information is shared with law enforcement

SARs and KYB

For KYB programs, SAR obligations mean:

  • Suspicious business behavior during verification may trigger filing
  • Ongoing monitoring that detects suspicious activity triggers SAR consideration
  • SAR filing decisions are separate from relationship decisions (you may file a SAR and continue the relationship, or file and exit)

Filing

SARs are filed electronically through FinCEN's BSA E-Filing system within 30 days of detecting suspicious activity.


Related: FinCEN | BSA | CTR | AML