Under Section 42 of the Criminal Justice (Money Laundering and Terrorist Financing) Act 2010, an Irish designated person who knows, suspects, or has reasonable grounds to suspect that another person is engaged in money laundering or terrorist financing must report. That report — a Suspicious Transaction Report, or STR — goes to both the Financial Intelligence Unit (FIU) of An Garda Síochána and the Revenue Commissioners.
The obligation sounds simple. Applying it without tipping off clients, destroying internal relationships, or missing the window — that's where it gets hard.
When is the threshold crossed?
"Knows, suspects, or has reasonable grounds to suspect" is a broad test. In practice:
- Knowledge — you have actual information the client is laundering
- Suspicion — something above mere speculation, a real feeling something is wrong
- Reasonable grounds — an objective test: would a reasonable person in your role suspect?
The last one catches firms out. Staff often say "I wasn't sure" — but the law doesn't require certainty. It requires reasonable grounds, assessed on the facts available.
The internal escalation step
Before anything goes to the FIU, staff must escalate internally to the Money Laundering Reporting Officer (MLRO). This is a Section 42(2) requirement and it's important for three reasons:
- It protects individual staff from having to judge alone
- It centralises decisions and creates a consistent standard
- It creates the audit trail Central Bank inspectors want to see
The MLRO's decision
The MLRO receives the internal report, assesses it, and either files an STR or records the reasons for not doing so. Either way, the decision must be documented. An MLRO who says "I decided it wasn't suspicious" without any record has failed a core obligation.
Crucial point
"No STR filed" is a perfectly valid MLRO decision — as long as the decision is reasoned and recorded. Firms fall over when they have internal reports but no documented disposition.
How and where to file
Ireland operates a dual-reporting regime:
- FIU Ireland — reports are filed through the Garda online system (goAML)
- Revenue Commissioners — reports are filed through Revenue's dedicated AML reporting channel
Both must be filed "as soon as practicable" after suspicion is formed. In practice, 24–72 hours is the maximum defensible window.
Content of an STR
A well-constructed STR contains:
- Subject identification — full name, DOB/incorporation, address, PPSN/CRO number where known
- Transaction details — dates, amounts, counterparties, instruments, accounts
- The grounds of suspicion — why the activity is suspicious, in specific terms
- Supporting documentation references (don't attach massive files; reference them and hold them available)
- Any linked prior STRs from your firm
Tipping off — the hardest part
Section 49 makes it a criminal offence to disclose to the subject of an STR, or to any other person, that a report has been made or is being contemplated, if that disclosure is likely to prejudice an investigation.
The practical effect: your normal client communications must continue as if nothing unusual has happened. You must not:
- Tell the client you've filed an STR
- Tell them you're ceasing to act because of an STR
- Share STR details with other staff who don't need to know
- Send internal emails that could be produced in a data subject access request
Training on tipping off is non-negotiable for every client-facing team member.
What happens after you file
The FIU may:
- Acknowledge receipt and take no further action
- Request more information
- Direct you not to proceed with a transaction (a "consent" regime applies)
The relationship continues on commercial terms unless you receive directions otherwise. A filing is not, in itself, a reason to terminate.
Common failures
- Delayed filings — the "we were gathering more information" excuse
- Vague grounds — "unusual transaction" instead of specific red flags
- Filing with FIU but not Revenue (or vice versa)
- No record of MLRO decision on internal reports that were not escalated
- Inadvertent tipping off via client comms
- Training gaps — staff unsure when to escalate
Training is the fix
Every major STR failure in Irish enforcement has a training gap at its root. The Harrington AML course includes a dedicated STR module with scenario-based escalation drills.
Book a 15-minute demo to see how we handle the STR module — including the tipping-off scenarios that catch even experienced staff.