Compliance
Structuring (Smurfing)
Definition
Structuring is the practice of splitting a large sum of cash into smaller transactions, or spreading it across days, locations or people, so that each one stays below a reporting or identification threshold and the paperwork it would trigger is avoided. When several people are used to make the deposits, often called smurfs, it is known as smurfing.
In the US, 31 CFR 1010.100(xx) defines structuring as conducting transactions in currency 'in any amount, at one or more financial institutions, on one or more days, in any manner' to evade currency transaction reporting, and 31 USC 5324 makes it a federal offence, punishable by up to five years in prison, even when the money itself is legitimate. In gambling, typical patterns are repeated buy-ins or cash-outs just under $10,000 at a US casino, or deposits and withdrawals kept just below a British casino's £2,000 customer due diligence threshold.
Key takeaways
- Structuring means breaking up cash transactions to stay under reporting or identification thresholds; using several people to do it is called smurfing.
- In the US it is a federal offence under 31 USC 5324 even if the funds are clean, because the crime is evading the report.
- Casinos must aggregate transactions by the same person across a gaming day, so splitting cash does not avoid a US currency transaction report.
- British casino guidance tells operators to look for customers deliberately spreading transactions to stay under the £2,000 CDD threshold.
Worked example
An illustrative pattern, not drawn from a real case.
A customer brings $27,000 in cash to a US casino:
- 10:15, main cage: buys chips for $9,500.
- 13:40, a table: buys in for $9,000 in cash.
- 18:05, a different cage: a companion buys chips for $8,500 and hands them to the customer.
No single transaction exceeds $10,000. But under 31 CFR 1021.313 the casino must treat multiple currency transactions as one when it knows they were made by or on behalf of the same person in the same gaming day, so this total of $27,000 requires a currency transaction report. The deliberate splitting, the use of a second person and the choice of different locations are also red flags that compliance staff should consider for a suspicious activity report.
Why it matters
Thresholds are only as strong as an operator's ability to see across them. Structuring exploits gaps between cages, tables, machines, properties and accounts, so the defence is joined-up data: player tracking that links cash activity to a person, multiple transaction logs, and transaction monitoring rules that look for repeated amounts just below a threshold, unusual frequency and activity spread across locations or linked people.
Land-based casinos face the classic version at the casino cage. Online, the pattern shows up as many small deposits or withdrawals, deposits made through several payment methods, or linked accounts used to stay under identification triggers. British casino guidance tells operators to consider whether a customer is deliberately spreading wagering or collection of winnings over several transactions to get around the customer due diligence threshold, which became £2,000 when the Money Laundering Regulations were amended on 30 June 2026.
Detecting structuring is not the end of the duty. A customer who appears to be avoiding a report or identification check should be considered for a suspicious activity report, and staff must avoid tipping the customer off. Operators that miss obvious structuring can face regulatory action in both the US and Great Britain. The AML and Financial Crime course covers threshold monitoring and escalation.
Structuring (Smurfing) vs Money mule
| Structuring (Smurfing) | Money mule |
|---|---|
| A technique: splitting or spreading transactions to keep each below a reporting or identification threshold. It can be done by one person alone. | A person who lets their account or identity be used to move money for someone else, knowingly or not, often to distance criminal proceeds from their source. |
Smurfing often relies on mules to make the split transactions, so the two typologies overlap. Monitoring needs to link accounts and people, not just watch amounts per account.
The bottom line
Structuring is splitting cash or deposits to stay under reporting and identification thresholds, and in the US it is a crime in its own right. Operators defend against it by aggregating activity across locations, accounts and linked people, and by escalating deliberate threshold avoidance as suspicious.
Sources
- 31 CFR 1010.100: General definitions (structure, structuring) - Legal Information Institute, Cornell Law School
- 31 U.S. Code 5324: Structuring transactions to evade reporting requirement prohibited - Legal Information Institute, Cornell Law School
- 31 CFR 1021.313: Aggregation - Legal Information Institute, Cornell Law School
- The prevention of money laundering and combating the financing of terrorism: Threshold approach - Gambling Commission
Frequently asked questions
What is structuring in AML?
Structuring is breaking a large cash amount into smaller transactions, or spreading it over time, locations or people, to avoid a reporting or identification threshold. In the US the classic target is the $10,000 currency transaction report. It is a well-known money laundering typology, and financial institutions, including casinos, are expected to detect and report it.
Structuring vs smurfing: what is the difference?
The terms overlap. Structuring is the general practice of splitting transactions to evade thresholds. Smurfing usually refers to a version that uses several people, the smurfs, to make the smaller deposits or purchases, which makes the pattern harder to see within any one account. Both are treated as red flags for money laundering.
Is structuring illegal if the money is legitimate?
In the US, yes. Under 31 USC 5324 the offence is structuring transactions for the purpose of evading reporting requirements, regardless of where the money came from. The maximum penalty is five years in prison, rising to ten in aggravated cases. Other countries approach it differently, but deliberate threshold avoidance is widely treated as grounds for suspicion.
What are red flags of structuring in a casino?
Common signs include cash transactions repeatedly just below a reporting or identification threshold, buy-ins split across cages, tables or properties, several people transacting for one customer, reluctance to provide identification as a total approaches a threshold, and online deposits or withdrawals broken into many small amounts or spread across linked accounts and payment methods.