Detecting Circular Fund Flows That Look Legitimate at Transaction Level

Table of Contents

Illustration of circular fund flows connecting multiple accounts in an AML transaction network.

Circular fund flows are sequences of financial transactions in which money moves through intermediary accounts or entities before returning to its origin or a related party. Individual payments may appear routine, but analysing the complete sequence across accounts, counterparties and time can reveal patterns that warrant further investigation.

In anti-money laundering (AML), circular transactions and round-tripping can be used to obscure the origin or movement of funds. However, similar patterns can also arise from legitimate business activities, including intercompany settlements, treasury operations, loan repayments and refunds. Circularity alone is therefore not proof of financial crime.

This guide explains the red flags of circular fund flows, why transaction-level monitoring may miss connected patterns, and how transaction monitoring, entity resolution, beneficial ownership checks and graph analytics can help AML teams identify and investigate suspicious activity.

What Are Circular Fund Flows in Money Laundering?

Circular fund flows are structured transactions where funds move through multiple accounts or legal entities and return to the same account, a related account, or the same beneficial owners, typically without clear economic rationale. In a circular flow arrangement, capital moves in loops without independent external demand entering the system, and money circulating among related entities may not create true economic value.

Several related terms appear in AML literature:

  • Circular transactions and circular transfers: funds cycling through a chain of accounts, often domestically or across different jurisdictions.

  • Round-trip transactions or round-tripping in money laundering: funds leave a country or entity, are transformed (e.g., relabeled as foreign investment or a loan), and return disguised.

  • Cyclical transactions: repeated circular patterns over multiple cycles.

These patterns usually occur during the layering stage of money laundering, where the objective is to distance illicit funds from their source. FATF typology reports consistently identify round-tripping and circular transfers as key layering schemes involving shell companies, over-invoicing, and entities in secrecy jurisdictions.

Hypothetical example: Account A (Dubai) sends USD 250,000 to B (London) for “consulting services.” B sends USD 248,500 to C (Hong Kong) labelled “project management fees.” C sends USD 249,000 back to A1-a company controlled by the same beneficial owner as A-within five days. Each payment looks routine. The circular flow only becomes apparent when the full chain is reconstructed.

Circular transactions obscure the origins of illicit funds and involve repeated movement of funds through multiple accounts. However, non-criminal scenarios can also create similar patterns: short-term intercompany loans, group cash pooling, mistaken payments and refunds, or legitimate business operations involving treasury management. Investigators must treat circular flows as red flags requiring further analysis, not as definitive evidence of criminal conduct.

Why Do Circular Fund Flows Look Legitimate at the Transaction Level?

Each transaction in a circular flow can carry plausible metadata: a valid invoice reference, a recognisable counterparty, a payment description like “loan repayment” or “inventory settlement.” Rule-based monitoring that evaluates single events against thresholds often clears these payments without issue.

The core problem is loss of context. Per-transaction review rarely shows the complete circular flow. Different transfers may be handled by different analysts, teams, multiple branches, or entirely separate financial institutions. The parties involved in one leg may never be connected to the parties in another leg without deliberate entity resolution.

Use of multiple accounts and affiliated entities fragments the flow further:

  • A customer with expected monthly turnover of USD 100,000 shows 10–12 payments of approximately USD 25,000 in and out across three related accounts.

  • Each payment falls within internal limits and has a valid SWIFT message code.

  • Payment descriptions are recycled (“consulting fee”, “inventory settlement”), and counterparties may be long-standing business relationships.

Techniques like structuring compound the problem. Smurfs deposit small amounts to avoid USD 10,000 reporting thresholds. Funnel accounts aggregate deposits from multiple locations into one account, and funnel accounts often facilitate rapid withdrawals to evade detection. High aggregate deposits with low account balances indicate funnel accounts, while deposits from various individuals can signal funnel account usage.

Data fragmentation across separate systems for wire transfers, cards, and wallets, combined with different core banking systems across subsidiaries and a lack of integrated beneficial ownership data, allows circular flows to pass as ordinary customer transactions and financial transactions.

Key Components of a Suspicious Circular Flow (A → B → C → A Example)

The A → B → C → A pattern is a canonical example of circular fund flows in AML casework. Its key components are:

  • Originator account (A): the source and ultimate destination of funds

  • Intermediary accounts (B, C, etc.): pass-through entities, often shell companies or SPVs

  • Return account (A or A1): same person, entity, or beneficial ownership as A

  • Time window: typically days or weeks

  • Amount similarity: near-matching amounts, reduced slightly by fees or FX spreads

Worked example (hypothetical, 2025): “Global Imports Pte Ltd” (Singapore) sends USD 500,000 to “Delta Commodities Ltd” (Latvia) for goods. Two days later, Delta sends USD 495,000 to “Nova Logistics SpA” (Cyprus) for logistics. Four days later, Nova returns USD 490,000 as a “profit distribution” to “Global Holdings Ltd”, a shell in Singapore controlled by the same UBO. No goods were shipped. Invoices are vague and unsigned.

The entities involved often share hidden relationships: common directors, ultimate beneficial owners, registered addresses, IP ranges, or devices that connect A, B, and C even when account names differ. Circular transactions can involve phantom shipments to disguise funds, and they often utilize shell companies to create false legitimacy.

Circular fund flows can artificially inflate asset prices and create misleading revenue signals. Circular transactions can inflate revenue without genuine exchanges-a pattern documented in cases where related vendors and customers generated approximately 60% of reported revenue through round-trip transactions.

In suspicious cases, there is little or no incremental economic value created across the chain. No genuine goods shipped, no new contracts, no independent third-party customers. This absence becomes clear only at flow-level analysis.

Red Flags of Circular Fund Flows and Circular Transactions

Red flags are warning signals which, when combined, should trigger deeper review. Each flag alone may have legitimate explanations. The following categories cover the key indicators compliance teams should monitor.

Transactional red flags:

  • Similar or matching outbound and inbound amounts across legs

  • Repeated payments between the same accounts or legal entities

  • Funds returning to the originator or related account within a short period

  • Multiple deposits and “slicing” of larger amounts into structured transactions

  • Rapid fund movement: incoming funds moved onward within minutes or hours (pass-through behavior)

  • Multiple wire transfers among the same parties with minimal variation

Entity and customer-level red flags:

  • Shared directors or beneficial owners across counterparties

  • Common mailing or registered addresses, overlapping phone numbers or emails

  • Newly created companies conducting high-volume cyclical transactions

  • Entities with no visible operational footprint or staff

Documentation red flags:

  • Missing or inconsistent invoices and generic contracts

  • Inability to provide evidence of actual delivery of goods or services

  • Invoices recycled with different dates and near-identical amounts

  • Under-invoicing or over-invoicing relative to market prices

Geographic and product red flags:

  • Flows routed through high-risk jurisdictions or secrecy jurisdictions

  • Use of trade finance, offshore accounts, or online gambling wallets

  • Cross-border transactions that do not fit the client’s stated business model

Trade-based money laundering (TBML) deserves particular attention. TBML disguises proceeds of crime through trade and exploits the complexity of international trade systems. TBML can involve over-invoicing or under-invoicing of goods; phantom shipments are a common TBML tactic, and TBML can create discrepancies between shipment documents and payments. Circular fund flows can distort price discovery, masking genuine market conditions, and circular financing can occur through reciprocal investments or strategic partnerships.

Examples of sectors affected by circular fund flows include healthcare, real estate, and technology. Circular financing can lead to greater interconnectedness and contagion in financial systems.

Red Flag

Why It Matters

Evidence to Review

Near-matching in/out amounts

Suggests pass-through with no value added

Transaction records, FX rate logs, fee schedules

Rapid transfers between accounts

Funds not used for the stated purpose

Timestamps, account statements, business records

Shared UBOs across counterparties

Apparent third-party transaction is actually self-dealing

Company registries, KYC files, beneficial ownership records

Missing or generic invoices

No documented commercial rationale

Contracts, bills of lading, customs filings, tax filings

Entities in secrecy jurisdictions

Increased difficulty verifying legitimacy

Jurisdiction risk rating, corporate registry data

Phantom shipments or no delivery proof

Trade-based laundering indicator

Shipping records, customs data, the same shipment documentation cross-checks

Newly formed entities with high turnover

Inconsistent with expected activity

Incorporation dates, financial records, staff records

How AML Teams Can Detect Circular Fund Flows in Practice

Detecting circular fund flows requires moving from isolated alert-based monitoring to holistic transaction pattern analysis across time, accounts, and related entities.

Establish a baseline. Build expected profiles for customers: normal turnover, counterparties, geographies, currencies, seasonality, and typical payment methods. This aligns with a risk based approach as recommended by FATF.

Link accounts and entities. Perform entity resolution using legal names, national IDs, tax numbers, device fingerprints, addresses, and beneficial ownership data to identify beneficial owners and cluster accounts controlled by the same person or group. Tools like PreScreening.io support party-level risk checks and AML name screening during this process.

Configure pattern-based monitoring. AML transaction monitoring systems can be configured to generate alerts based on sequences: funds leaving an account and returning within X days with less than Y% variance in amount. Solutions like ZIGRAM’s Transact Comply support scenario-based monitoring that goes beyond single-transaction rules.

Analyse direction, sequence, and timing. Look for cyclical transactions, multiple deposits followed by a single consolidation transfer, and chains like A → B → C → D that eventually route back to A or A’s group.

Integrate screening and due diligence. Use Due Diliger reports for corporate counterparty analysis and Dragnet Alpha for adverse media monitoring about entities involved in suspected circular flows. Financial regulatory bodies increasingly scrutinize circular fund flows for compliance risks, making this integration essential for an effective AML program.

Why Traditional Transaction Monitoring Often Misses Circular Patterns

Many legacy AML systems are built around per-transaction rules-single large cash deposits, high-value wires to a high-risk country, or matches against sanctions lists. These rules evaluate whether an individual payment breaches a threshold, not whether similar or mirrored transactions recur over days or weeks across different accounts.

Layering obscures the origin of illicit funds through complex transactions. Layering often involves multiple accounts and jurisdictions to evade detection, and shell companies are commonly used in layering to hide beneficial ownership. Layering creates a convoluted trail that complicates financial investigations, and detection of layering is crucial to prevent integration of laundered funds into the legitimate economy.

Fragmentation compounds the problem. Activity may span current accounts, trade finance lines, cards, and correspondent banking relationships across subsidiaries-meaning no single system holds a complete view. Data quality issues-inconsistent counterparty names, missing identifiers, free-text payment purpose fields, and incomplete KYC files-reduce the ability to link related transactions into a circular pattern.

Not every traditional system fails. Sophisticated rule engines and scenario-based transaction monitoring can detect some circular flows, but coverage depends on parameter design, tuning, and the institution’s data integration maturity. Institutions should periodically test and backtest scenarios against known typologies of round-tripping in money laundering, using internal case libraries and public enforcement actions as benchmarks.

How Graph Analytics and Network Analysis Help Detect Circular Fund Flows

Network analysis visualizes financial relationships among entities by representing accounts and legal entities as nodes and financial transactions as directed edges with attributes such as date, amount, and currency. It maps entire transaction ecosystems for better detection of money laundering and helps identify clusters of accounts with suspicious transactions.

Circular fund flows appear as cycles in a transaction network-A → B → C → A. Graph analytics algorithms can identify such cycles within defined time windows (7, 30, or 90 days) and flag them for review.

Configurable parameters investigators should consider:

  • Maximum cycle length (number of intermediary accounts)

  • Acceptable deviation in amounts (to allow for FX spreads and fees, typically ±5–10%)

  • Minimum and maximum time between legs

  • Number of repeated cycles needed before escalation

Key network metrics for circular transaction detection include betweenness centrality (accounts acting as key intermediaries in the money trail) and degree (nodes with unusually high in/out connectivity). Research published in the Journal of Anti-Corruption found that network-derived metrics differ significantly between accounts involved in laundering-like behavior and normal accounts. A systematic review of 97 studies confirmed that models using network analysis combined with machine learning outperform transaction-only models.

Network analysis reveals patterns obscured in traditional transaction monitoring and can uncover shell companies involved in laundering operations. It complements rather than replaces traditional AML transaction monitoring: rules still detect simple red flags, while network analysis reveals higher-order suspicious transaction patterns across customers and counterparties.

Validating a Suspected Circular Flow: Investigation Workflow

Detection is only the first step. Investigators must validate whether a flagged circular flow represents suspicious activity requiring a SAR/STR or has a plausible, documented commercial explanation.

Step-by-step workflow:

  1. Reconstruct the timeline. Map every leg of the suspected flow with dates, amounts, currencies, and channels. Include fees, FX conversions, and minor variances.

  2. Map all entities and accounts. Identify every legal entity and natural person involved. Use corporate registries, KYC onboarding data, and beneficial ownership records.

  3. Confirm links. Verify connections through beneficial ownership, shared directors, addresses, IP overlaps, or device fingerprints. This is where efforts to identify beneficial owners become critical.

  4. Calculate metrics. Assess amount variance across legs, frequency of similar cycles, and ratio of circular flow to total turnover.

  5. Evaluate economic purpose. Check contracts, invoices, shipping documents, tax filings, and correspondence. Verify existence of goods or services. Assess whether the volume and direction of payments match the declared business model or constitute a complex web of self-dealing.

  6. Cross-check counterparties. Use due diligence tools, corporate registries, sanctions lists, and adverse media solutions. Cross-referencing with Dragnet Alpha and Due Diliger can surface suspicious behavior or adverse media about entities in the chain.

  7. Consider alternative explanations. Treasury cash pooling, genuine loan arrangements, group-level netting of payables and receivables, refunds, and income model adjustments can create patterns that resemble dirty money flows. Document how each was assessed and ruled in or out.

  8. Escalate and document. Summarise rationale, record evidence reviewed, link to prior alerts, and follow internal escalation policies and regulatory expectations for anti-money laundering reporting. Non-compliance with reporting obligations carries significant regulatory risk.

Strengthening Circular-Flow Monitoring in Financial Institutions

Robust detection of circular fund flows requires a combination of risk-based AML program design, better data integration, and ongoing scenario refinement-not a single algorithm change.

Governance: Define clear risk appetite regarding circular flows. Update AML policies and procedures to include circular transaction typologies. Align internal training to layering and round-tripping in money laundering. Ensure the financial sector your institution operates in has appropriate coverage.

Data foundations: Consolidate transaction flows across products and channels. Improve counterparty identifiers and store beneficial ownership details. Integrate external data sources. High quality data is the foundation of effective fraud detection and suspicious activity detection.

Monitoring design: Create specific scenarios targeting:

  • Same or similar amounts leaving and returning within a set period

  • Rapid multiple deposits followed by consolidation

  • Unusual intercompany circular flows without documented rationale

  • Unusual transaction behavior relative to the customer’s established baseline

Prioritisation and explainability: Risk-score money flows based on amount, jurisdictions, counterparties, and documentation quality. Ensure investigators can explain why an alert was triggered to internal audit and regulators. Actionable best practices include documenting the economic analysis performed and the sophisticated schemes considered.

Tools like Transact Comply for transaction monitoring, PreScreening.io for screening and KYC checks, and Due Diliger for entity due diligence can support the operationalisation of circular-flow monitoring within existing AML programs. Periodic testing against known laundering operations and money laundering schemes ensures scenarios remain effective as money launderers adapt their methods.

Frequently Asked Questions About Circular Fund Flows

What is a circular fund flow? A circular fund flow is a sequence of financial transactions where funds leave an account, pass through one or more intermediary accounts or entities, and return to the original account or a related account controlled by the same beneficial owner. The cycle typically occurs within a short timeframe and with limited or no genuine economic purpose. Circular fund flows can be legitimate or problematic depending on the context and economic rationale.

Is round-tripping always money laundering? No. Round-tripping in money laundering is a known typology, but similar circular patterns can arise from legitimate tax planning, group financing, error correction, or treasury operations. Context, documentation, and the presence or absence of genuine commercial rationale determine whether a round-trip transaction is suspicious.

How can circular transactions be detected? Through a combination of AML transaction monitoring scenarios designed for sequences, transaction pattern analysis across multiple accounts, network analysis, and graph analytics in AML. Detection also depends on high quality data, entity resolution, and investigator review of individual transactions and their broader context within the financial ecosystem.

What is the difference between circular transactions and layering? Layering is a stage of money laundering where criminals obscure the origin of illicit funds through complex, layering schemes involving multiple transactions. Circular transactions are one technique used in layering but can also appear in legitimate contexts like intercompany settlements or refund cycles.

How does graph analytics help detect circular fund flows? Graph analytics represents transaction networks as nodes and edges, enabling cycle detection algorithms to find closed loops where funds return to their origin. Centrality metrics highlight key intermediary accounts. These network-level views reveal unusual patterns missed when monitoring individual transactions in isolation.

Why are beneficial ownership checks important for detecting circular flows? Different account names can hide the same controller. Beneficial ownership in AML investigations links accounts that appear unrelated, revealing that seemingly independent entities share the same UBO. Without this, offshore accounts and shell companies in the financial system can mask genuine circularity across different jurisdictions.

Can legitimate business transactions appear circular? Yes. Treasury operations, intra-group settlements, refunds, loan repayments, and legitimate transactions within the legitimate economy can create circular flow patterns. This is why AML teams must rely on evidence, financial records, business records, and proportional judgment rather than suspicious patterns alone.

Conclusion and Next Steps for AML Teams

Circular fund flows are designed to hide in plain sight. Each transaction appears unremarkable; the sequence tells a different story. Detecting these patterns requires moving beyond per-transaction rules toward pattern- and network-based analysis that connects transaction behavior, entity relationships, and timing across the full money trail.

Suspicious transaction patterns-including circular transactions and round-trip transactions-are indicators that should prompt structured investigation, not automatic conclusions about criminality. An enhanced due diligence process, combined with transaction network analysis, gives investigators the tools to separate genuine economic activity from sophisticated schemes designed to cycle funds through a complex web of entities.

Practical next steps for financial institutions include reviewing existing AML transaction monitoring scenarios for circularity coverage, assessing data quality and beneficial ownership capture, and piloting basic transaction network analysis. ZIGRAM provides RegTech solutions and data assets that help regulated institutions strengthen fraud detection, AML programs, and investigation workflows.

Explore ZIGRAM’s transaction monitoring and AML screening capabilities to understand how tools like Transact Comply and PreScreening.io can support your circular-flow detection efforts.

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