Suspicious Transaction Report (STR)

A suspicious transaction report (STR) is a confidential report that a financial institution or other regulated business submits to its country's financial intelligence unit (FIU) when it suspects, or has reasonable grounds to suspect, that funds are the proceeds of crime or are related to terrorist financing. The report describes the customer, the transactions and the reasons for suspicion, and the FIU analyses it alongside other information before sharing intelligence with law enforcement.

STR is the term used in the FATF recommendations and in the laws of many countries, including much of Asia, Africa and the Middle East; Australia calls its equivalent a suspicious matter report. The United States and the United Kingdom use the term suspicious activity report (SAR), and the European Union's rules refer to reporting suspicious transactions or activity. The names differ, but the purpose and the core obligations are largely the same.

FATF Recommendation 20 requires countries to oblige financial institutions to report promptly to the FIU when they suspect, or have reasonable grounds to suspect, that funds are criminal proceeds or related to terrorist financing. Recommendation 23 extends the duty to designated non-financial businesses and professions, such as casinos, dealers in precious metals and stones, real estate agents, lawyers, notaries and accountants in certain activities. Countries implement these standards in national anti-money laundering laws, which set out who must report, the threshold of suspicion, deadlines, the format and the protections for reporters.

The reporting duty usually applies whatever the amount, and it covers attempted transactions as well as completed ones. A business that turns away a customer because of suspicion may still need to file a report. Deadlines vary by country, from a set number of days after suspicion arises to an obligation to report promptly or immediately.

Most FIUs prescribe a reporting form or electronic format. Typical contents include:

• Subject details. Names, dates of birth, addresses, identity documents, account numbers and related parties of the customers or entities involved.
• Transaction details. Dates, amounts, currencies, counterparties and channels of the transactions in question.
• Grounds for suspicion. A narrative explaining what was unusual, how it was detected and why it does not fit the customer's known activity or source of funds.
• Actions taken. Whether the firm blocked funds, closed the relationship or sought consent to proceed.

The quality of the narrative is critical, since FIU analysts depend on it to understand the case. Many FIUs use the goAML software developed by the United Nations Office on Drugs and Crime to receive and process reports electronically.

Within a firm, potential suspicion usually arises from transaction monitoring alerts, staff referrals, sanctions or adverse media hits and requests from law enforcement. Analysts review the alert, gather information, and decide whether it amounts to suspicious activity. Cases that meet the threshold are escalated to the money laundering reporting officer or equivalent, who decides whether to file. Firms document decisions not to file as well as decisions to file, because supervisors review both.

STRs are confidential. The anti-tipping-off rule forbids telling the customer or third parties that a report has been made or that an investigation may follow. In return, laws protect reporters who act in good faith from civil and criminal liability for breach of confidentiality. In some countries, such as the United Kingdom, a reporter can also seek consent from the FIU before carrying out a suspicious transaction, which provides a legal defence if consent is given.

FIUs use STRs to build cases, identify networks, support investigations and produce strategic analysis of trends, such as new money mule or scam typologies. Reports may also be shared with foreign FIUs through international cooperation channels.

Critics point out that very large volumes of reports, many filed defensively to avoid regulatory criticism, can overwhelm FIUs and make it harder to find the most useful information. Feedback from FIUs to reporters is often limited, so firms struggle to know whether their reports are valuable. Reforms in several countries aim to improve report quality, encourage public-private information sharing and use data analytics to prioritise cases, while also considering how reporting obligations should apply to new sectors such as crypto-asset services and counter-terrorism financing controls.