Where Do I File an STR?
STRs are filed through the STRO Online Notices And Reporting (SONAR). Members of the public without a business filing can also lodge an STR directly with the Suspicious Transaction Reporting Office (STRO). Use the STR form on the police website, and submit it by post or in person.
What Should I Include in My STR?
STRO's form requests the following transaction details:
Amounts involved
Parties on either side
Account information
The most important part is your basis of suspicion, and you must write this plainly: what looked wrong and why. You should also attach all supporting documents you have on hand, along with relevant receipts, correspondence, and internal notes.
The STR Filing Process
1. Set up SONAR access through your CorpPass administrator.
2. Note the details as soon as the concern comes up. Names, amounts, what was said, while it's still fresh, rather than reconstructing it from memory later.
3. Decide internally who actually files. A named person avoids the report stalling because nobody was sure it was their job.
4. Submit through SONAR with the transaction details and your basis of suspicion written out clearly.
5. Keep your own copy of what was submitted and when, separate from SONAR's own record.
Do Not Disclose Your STR with Anyone
Once you've filed an STR, you’re prohibited from informing anyone under Section 57 of the CDSA.
What Happens After You File an STR?
STRO reviews the report and may follow up with further questions if your basis of suspicion needs clarification. Filing an STR in good faith doesn't require you to be right, as you're deemed to have submitted a report under reasonable grounds for suspicion. You're not expected to investigate further yourself once you've submitted your STR.
Summary of How to File an STR
Question | Answer |
Where do you file an STR? | SONAR (police.gov.sg/SONAR), via CorpPass |
Where do individuals without a business account file? | STR form, submitted by post or in person to STRO |
What must the report include? | Transaction details, parties, basis of suspicion, supporting documents |
Can you tell the customer you filed? | No. Tipping off is an offence under CDSA Section 57. |
Do you need to be certain before filing? | No. Reasonable grounds for suspicion are the standard. |
Set Up Your STR Process with Mezzanine Enterprise
As part of Mezzanine Enterprise’s Governance, Risk & Compliance (GRC) and risk management support, we help retailers set up SONAR access and name who's responsible for filing. We build the internal process before an actual transaction forces the question.
Talk to us now to get started today.
5 Oct 2026
You've Spotted a Money Laundering Red Flag. Here's How to File a Suspicious Transaction Report (STR)
Celeste Cordeiro
Last Updated:
12 Oct 2026
It’s one thing to recognise a money laundering red flag. Knowing what to do about it is another thing entirely.
In this guide, we show you how to file a Suspicious Transaction Report (STR), who to inform, and the precautions you must take when taking action.
