A Suspicious Activity Report (SAR) is a report used to flag suspicious activities within the financial system. It helps authorities detect and prevent financial crimes such as money laundering, terrorist financing, and fraud. By reporting suspicious transactions, businesses contribute to a safer and more transparent financial ecosystem.
In this article, you’ll gain a clear understanding of what SARs are, how and when they should be filed, and why they matter for your organisation. It’s a practical guide for anyone working with compliance, finance, or risk management.
Regulation and origin of SARs
The requirement for SAR reporting emerged in the 1970s alongside growing efforts to combat money laundering. In the United States, the Bank Secrecy Act (BSA) of 1970 became one of the first laws mandating the reporting of suspicious activities.
Since then, many countries have developed similar frameworks, often based on recommendations from international organisations like the Financial Action Task Force (FATF).
In the EU, SAR reporting is a key part of the Anti-Money Laundering Directives (AMLD), which member states are required to implement through national legislation.
Examples of suspicious activities
Here are three common examples of activities that may trigger a SAR:
- A customer makes an unusually large cash deposit without being able to explain the source.
- A business partner insists on using unnecessarily complex payment structures.
- A transaction involves countries known for weak anti-money laundering and counter-terrorism measures.
Common patterns of suspicious activity
Suspicious activities often follow certain recurring patterns:
- Structured deposits, where small amounts are deposited repeatedly to exceed reporting thresholds.
- Sudden changes in customer behaviour, such as a client shifting from small to very large transactions.
- Complex chains of transactions, with money moving through numerous accounts across different countries to hide its origin.
Recognising these patterns is critical to detecting and preventing financial crime early. Read more about key alert triggers that can be implemented to strengthen your AML programme.
