BA001 · Correspondent Banking

Structuring

Structuring — known colloquially as "smurfing" — is the deliberate breaking-up of cash deposits into amounts just under a currency-transaction reporting threshold (in the US, the $10,000 CTR line) to keep individual deposits below the reporting trigger while the account accumulates a large aggregate cash position. The structured cash is then moved onward — wired out to a single beneficiary — turning a pattern of small, evasive deposits into a laundering leg.

The finding is a clustering finding: it lives in the share of cash deposits sitting just under the reporting line, how tightly those deposits cluster in time, how many distinct branches or ATMs they are spread across, and how much of the structured cash is subsequently wired to one downstream beneficiary.

Risk indicators

Sub-threshold Clustering

• High share of cash deposits sitting just under the CTR reporting line
• Deposit amounts clustered near (but under) the threshold rather than spread naturally
• Round-number deposits inconsistent with the account's declared cash profile

Temporal Clustering

• Multiple deposits inside a rolling 7-day window
• Deposit cadence inconsistent with normal payroll/business cash cycles

Multi-location

• Deposits spread across several branches or ATMs on the same day or in the same window
• Geographic spread inconsistent with the customer's declared home location

Aggregation-to-transfer

• Structured-in cash wired out to a single downstream beneficiary
• Wire timing shortly after the structured cash accumulates (short dwell)

Investigation actions

1. Resolve the account, its home branch, and its beneficiary.
2. Compute the sub-threshold cash ratio (sub-threshold deposits / total cash deposits).
3. Compute the temporal clustering of deposits inside a rolling 7-day window.
4. Count the distinct branches/ATMs the deposits are spread across.
5. Compute the aggregation-to-transfer ratio (wired out / structured in).
6. Score each of the four components against its band cut-lines.
7. Aggregate the weighted exposure score; escalate at or above the threshold.

Detection logic

1. Resolve the account, its home branch, and its beneficiary. 2. Compute the sub-threshold cash ratio (sub-threshold deposits / total cash deposits). 3. Compute the temporal clustering of deposits inside a rolling 7-day window. 4. Count the distinct branches/ATMs the deposits are spread across. 5. Compute the aggregation-to-transfer ratio (wired out / structured in). 6. Score each of the four components against its band cut-lines. 7. Aggregate the weighted exposure score; escalate at or above the threshold.

Related typologies

Curated from fc-06-correspondent-banking-analytics-toolkit/typologies/BA001_Structuring.md