Cum-cum: how a dividend tax becomes a trading margin

The cum-cum investigation, part 1

In cum-cum arrangements, shares change hands temporarily around a dividend and the tax advantage is shared between an investor and its intermediary. The company distributes the same income, but the route taken by the securities changes the amount reaching the French tax authority. Crédit Agricole CIB’s public agreement with the financial prosecutor lets us follow that detour and understand how it was priced. S1, paragraphs 22–35 S3, paragraph 1

The agreement describes facts acknowledged by the bank and the economics of the transactions identified. It provides a public basis for connecting ownership of the shares, receipt of the income and the commitments made to the foreign investor.

A tax charge attached to the recipient

When a French company distributes a dividend falling within the rules for non-resident recipients, part of the payment is withheld and remitted to the French tax authority. The recipient receives the balance. Withholding tax is collected within the payment chain, rather than through a later French tax payment by the investor. S3, paragraph 1

The amount depends on the recipient’s status, domestic legislation and the applicable tax treaty. Treaties allocate taxing rights between the source country and the investor’s country of residence. They may provide a reduced rate or an exemption, making an appropriately claimed refund an ordinary part of cross-border investment. The investor’s final tax position also depends on residence-country taxation and the relevant double-taxation relief. S13

The cum-cum arrangements described by France’s Conseil d’État exploit the difference between recipients. A non-resident temporarily transfers shares to someone outside the scope of the relevant withholding charge, around the dividend’s ex-date. Part of the dividend’s value then returns to the original investor, either through a payment or through the financial terms of related contracts. S3, introduction and paragraphs 1, 5, 8–9

That makes the intermediary’s tax position an economically valuable feature of the trade. Understanding the source of that value requires three connected views: what the company distributed, who was legally entitled to receive it, and what the recipient had promised the foreign investor. The issuer’s payment record captures only part of that story.

When a share loses its entitlement to the next dividend

Shares trade with, and then without, the right to an announced distribution. The ex-dividend date marks that boundary. The payment date is when the money is actually paid. A record date determines which holders are recorded for the distribution under the relevant market’s arrangements. These dates have different functions, and the actual transaction calendar matters. S5

A dividend leaves the company’s assets. Holding everything else constant, detachment therefore reduces the share’s theoretical value. The payment to the shareholder accompanies that adjustment; the advantage sought in cum-cum comes from the tax treatment of the income. S5

The tax opportunity arises because two recipients may face different deductions from the same income. An investor otherwise subject to withholding may receive more by obtaining equivalent value through a differently taxed counterparty. Financing, fees and risk still matter. The calendar establishes the dividend entitlement; the contracts determine how its economic value is shared.

Method and scope

Generic interposition schematic based on the French agreement and Conseil d’État opinion. Custody chains, collateral and hedging are simplified. Actual dates depend on the market and contracts; distances between phases are not to scale. In a theoretical ex-dividend example, a €100 share paying €2 becomes worth €98 after detachment, with everything else unchanged, plus the entitlement to €2. Combined value remains €100. This is a valuation illustration rather than a market-price forecast.

In the clearest version, shares move temporarily. The investor transfers them before the relevant dividend entitlement is fixed. The intermediary receives the distribution under the treatment applicable to its position. The combined arrangements provide for the return of shares and a settlement reflecting the dividend. The Crédit Agricole CIB agreement describes this interposition and identifies several possible instruments, including securities loans, futures and total return swaps. S1, paragraphs 22–24

The diagram deliberately compresses the custody and payment chain. Custodians, paying agents, collateral and hedging transactions can generate many more entries. A complete reconstruction has to connect those records to the central question: who ultimately obtains the dividend’s value, in what form, and under which tax treatment?

One hundred euros, two allocations

Our central comparison uses a €100 gross dividend, an assumed 15% withholding rate in the reference case and 90% of the dividend returned to the investor in the modelled arrangement. The €100 scale is our teaching device. The 90% and 85% figures come from the judicial agreement’s example. None of these inputs is a market average or a universal tax rate applicable today. S1, paragraph 34

The same distribution therefore leaves the investor €5 better off and the intermediary with €10 before its costs and taxes. Together, their advantage equals the €15 withholding absent from the second route.

Method and scope

Paragraph 34 of the agreement gives examples of 90% of the gross dividend against 85% or 75% after withholding. The l0g model scales the dividend to €100 and uses the 90/85 comparison: €85 for the investor and €15 withheld in the reference case; €90 for the investor and €10 retained gross by the intermediary in the model assuming no withholding. Investor improvement: 90 − 85 = €5. Allocation: 5 + 10 = €15. Calculated variants: returning €92 gives a €7 improvement and €8 retained; returning €88 gives €3 and €12 respectively. For dividend D, reference withholding rate t and fraction returned q: improvement = Dq − D(1 − t), retained amount = D(1 − q). Their sum is Dt. Financing, collateral, hedging, fees, the parties’ own or foreign taxes, reassessments and penalties are outside the model. Rates are hypothetical and amounts gross; this isolated withholding difference leaves a national fiscal-loss calculation to be established separately.

Calling the intermediary’s €10 a net banking profit would go beyond the model. It is gross value retained before financing, collateral, hedging, operating costs and the intermediary’s own tax charges. The ECB’s account of securities lending specifically describes borrowing fees, collateral costs and the legal and administrative expense of establishing a lending relationship. S4

That €15 difference concerns French withholding within an isolated example. A national fiscal-loss estimate requires actual transactions, their applicable tax treatment, other relevant taxes and subsequent recoveries.

Economic exposure can survive a change of legal owner

Legal ownership and exposure to a share’s performance are separate concepts. Ownership concerns the security and its associated rights. Economic exposure concerns the gains, losses and income an investor experiences, whether through ownership or a contract. Derivatives can pass some of that performance to a party that does not hold the underlying share. French sources expressly identify futures and total return swaps (TRS) among the instruments used in dividend arbitrage. S1, paragraph 23 S3, paragraph 2

Consider a contract transferring the share’s price performance and a dividend-related component. Its recipient can obtain exposure resembling share ownership while the security sits elsewhere. A financing payment may run in the other direction, and adverse price changes may generate amounts owed by the investor. The precise contractual terms govern the cash flows. The next diagram isolates that relationship; it does not reconstruct an individual Crédit Agricole CIB contract.

Method and scope

Qualitative depiction of two sets of rights: ownership of the security and contractual transmission of its performance. Flows depend on terms, financing and the direction of price changes. The chart shows possible components rather than an individual Crédit Agricole CIB contract. Tax beneficial ownership requires a legal assessment of the right to use and enjoy income under the cited French administrative guidance.

Dividend value can also be embedded in a price. In its January 2025 opinion, the Conseil d’État explains that a futures price can incorporate part of the relevant value transfer. An investigator who searches only for a payment labelled “dividend” may therefore miss economically connected terms. Transactions have to be read together. S3, paragraphs 5 and 7–10

This is one reason the legal analysis becomes demanding. A payment record shows its immediate recipient. Establishing who could use the money, and how its value was passed on, requires the obligations behind that record. Economically similar outcomes can be expressed through different legal categories, such as share income, a contract price or remuneration associated with a securities loan. Taxing those outcomes requires a legal basis that supports the treatment adopted.

Beneficial ownership adds another question. French administrative guidance published in March 2026 focuses on the right to use and enjoy the income without a legal or contractual obligation to pass it to someone else. Retaining market exposure can inform the economic analysis; it does not by itself settle beneficial ownership for tax purposes. The rights, obligations and actual freedom to use the income require their own assessment. S8, paragraph 30

Two routes through the tax difference

The Conseil d’État distinguishes domestic cum-cum, involving a French tax-resident intermediary, from cross-border or external cum-cum, involving a non-resident intermediary exempt because of a treaty or its status. In the arrangements described, the original investor seeks to obtain the benefit of a treatment unavailable to it directly. “Domestic” describes the intermediary’s residence, not a transaction confined to France. S3, introduction

The distinction changes the work an investigation must do. The first route directs attention to the French bank’s obligations to its foreign counterparty. The second also requires examining the non-resident intermediary’s residence, status and treaty entitlement. In either route, an exemption genuinely available under the law has to be distinguished from abusive interposition. The Conseil d’État stresses the need for safeguards allowing parties to demonstrate a non-abusive purpose or effect. S3, paragraphs 3 and 6

Building a case from trading records

Securities lending serves ordinary market functions. A borrower may need shares to complete delivery, meet a client’s demand or support a hedge. It generally provides collateral and pays a fee. The ECB describes these legitimate uses in its own explanation of the market. They are an essential part of the context when assessing a dividend-period transaction. S4

The Crédit Agricole CIB agreement makes this distinction within the bank’s own business. It states that most of the Equity Finance desk’s intermediation met hedging needs, including those associated with employee share plans, while identifying particular transactions as dividend arbitrage. It also records that the internal investigations had not identified a sales-solicitation policy encouraging clients to undertake such arbitrage. These points favourable to the bank belong in the account alongside the acknowledged facts. S1, paragraphs 28–36

The agreement also records that transaction volumes and the associated income became residual after internal restrictions introduced in 2019. S1, paragraphs 37–38

The agreement describes indicators including concentration around dividend dates, counterparties’ residence, pricing and unusually high returns relative to associated risks. An all-in quote expresses the fraction of the dividend returned to the counterparty. In the transactions analysed, that pricing helped explain how the tax advantage remunerated the intermediation. The indicators derive meaning from their combination and from the underlying evidence. S1, paragraphs 25 and 33–35

Testing that account at transaction level would require trade confirmations, lending or derivatives agreements, financing terms, settlement instructions, tax profiles and internal control records. The task is to compare the economic purpose asserted with the obligations actually undertaken. Heavy trading during dividend season can prompt an investigation. The records determine what the investigation can establish.

Crédit Agricole CIB’s agreement and its legal status

Crédit Agricole CIB acknowledges facts described in the agreement as occurring between 2013 and 2022. The financial prosecutor considers them capable of being characterised as aggravated laundering of aggravated tax fraud. Signed on 5 September 2025 and validated on 8 September, the agreement provides for a public-interest fine of €88,247,869. S1, paragraphs 39–41 and 57 S2

A convention judiciaire d’intérêt public, or CJIP, is a negotiated resolution within the French criminal-procedure framework. Its validation declares neither guilt nor a conviction, as the agreement expressly states. The amount agreed is a payment obligation; confirmed receipt would require separate evidence. S1, paragraphs 58–61

Proceedings have also advanced for HSBC Bank plc. The PNF announced a CJIP signed on 6 January and validated on 8 January 2026, concerning transactions involving its Paris branch during 2014–2019. S12

Cum-cum and cum-ex take different fiscal routes

The similar names can obscure an important difference. The cum-cum model in this article removes or reduces withholding through a differently taxed intermediary. The German cum-ex arrangements examined by the Bundestag inquiry involved tax credits or refunds without corresponding tax collection, including multiple claims against tax withheld only once. S3, paragraph 1 S11, page 76

Method and scope

Mechanism comparison. The cum-cum model relies on interposition and different tax treatment. The cum-ex arrangements described on page 76 of the German report involve credits or refunds without corresponding withholding, including multiple claims for tax withheld once. These sources concern separate frameworks and cases. The drawing supplies neither an aggregate loss estimate nor a legal finding about a particular trade.

The advantage arises at a different point in the fiscal chain. In our cum-cum example, parties share the value of withholding avoided. In the cum-ex arrangement described by the German report, an unjustified tax claim generates a credit or refund. The evidence, fiscal-loss calculation and legal analysis must follow the relevant route. A conviction in one category establishes no responsibility in the other.

Tax law follows the transferred value

France’s 2025 Finance Act extended the framework to value transfers and instruments whose economic effect resembles share ownership. Since 1 January 2026, certain dividends paid to residents of countries whose treaty with France provides a full exemption have first been subject to withholding. The recipient may then claim a refund by establishing its treaty entitlement. The French tax administration’s guidance sets out the treaties covered and the exemptions. S7 S8, paragraphs 1–20 S9 S15

Past transactions also raise a question of taxpayer safeguards. In January 2026, the Conseil d’État recalled the protection available to a taxpayer that complied with the guidance published at the time. In its October answer, the government maintained that artificial arrangements constituting an abuse of law remain open to challenge. Both the protection invoked and the substance of the arrangement therefore require examination in each case. S14, paragraphs 4–8 S10

Legal developments from 2023 to 2026

On 8 December 2023, the Conseil d’État annulled administrative guidance that extended withholding beyond the legislation then in force. It expressly preserved the routes under Article 119 bis A and the abuse-of-law procedure. This historical ruling must be read with the rules governing each transaction. S6, paragraphs 3–8.

Article 96 of the Finance Act dated 14 February 2025 introduced beneficial owners into Article 119 bis and extended Article 119 bis A to value transfers, combinations of transactions and instruments with a similar economic effect. The safeguard in I-3 requires both a purpose and an effect primarily other than obtaining the tax advantage. The new II alone took effect on 1 January 2026; administrative guidance followed on 16 March. The indexed consolidated Article 119 bis A is in force from 1 July 2026. S7, S8, S9, S15.

On 20 January 2026, decision no.505127 held that a challenge to paragraph 4 of the 17 April 2025 guidance, withdrawn on 24 July 2025, had become moot. It recalled the Article L.80 A safeguard for taxpayers complying with the guidance then published, without deciding the withdrawn passage’s lawfulness or a particular transaction. In its Senate answer published on 15 October 2026, the government maintained that the safeguard cannot be invoked for artificial arrangements constituting an abuse of law. The court’s reminder and the ministry’s position retain their respective scopes. S14, paragraphs 4–8, S10.

The shares show the route; the contracts and each participant’s tax position explain its outcome. Following them makes it possible to identify who kept the value, then assess the tax due and responsibility for each arrangement.

Further reading

• Barclays’ private-credit swaps: following the risk through the hedge.
• Banks: the cost of the December snapshot.
• Savings: how 50 index points change the risk behind a 10.5% target.

Sources and scope

Public-document investigation as of 27 October 2026. Individual contracts and unpublished internal reports remain outside the material examined. The models are educational illustrations, distinct from market statistics.

1. S1 · France’s National Financial Prosecutor / Ministry of Justice · 2025-09-05 · Accessed: 2026-10-27Signed public-interest judicial agreement
   Passages and scope

   2025-09-05. Printed pp.4–6 and 8; paragraphs 22–26, 28–41 and 57–61.

   PDF viewer numbering is one page higher.

   Signed agreement, acknowledged facts and illustrative pricing. Individual contracts and the unpublished internal investigation remain outside the public material examined.

2. S2 · France’s National Financial Prosecutor / Ministry of Justice · 2025-09-08 · Accessed: 2026-10-27PNF release on the Crédit Agricole CIB agreement
   Passages and scope

   2025-09-08. Page 1.

   Signature and validation dates and the fine agreed.

   An obligation to pay is distinct from confirmed receipt.

3. S3 · Conseil d’État · 2025-01-27 · Accessed: 2026-10-27Opinion on strengthened dividend-arbitrage withholding rules
   Passages and scope

   2025-01-27. Introduction; opinion paragraphs 1, 3–10 and 12–15.

   The government’s questions and positions are distinct from the Conseil d’État’s opinion.

   A proposed framework must be read with the enacted legislation.

4. S4 · European Central Bank · 2016-12-08 · Accessed: 2026-10-27What is securities lending?
   Passages and scope

   2016-12-08. Definition, uses, collateral and costs.

   Used for general lending mechanisms.

   Its historical settlement timetable is not applied to French markets in 2026.

5. S5 · U.S. Securities and Exchange Commission / Investor.gov · Accessed: 2026-10-27Ex-Dividend Dates: When Are You Entitled to Stock and Cash Dividends
   Passages and scope

   Publication date not stated on the page examined. Explanation of entitlement, ex-date, payment and price adjustment.

   US educational source used for concepts.

   Its US calendar and settlement examples are not transposed to France.

6. S6 · Conseil d’État · 2023-12-08 · Accessed: 2026-10-27Decision no.472587
   Passages and scope

   2023-12-08. Paragraphs 3–8.

   Historical annulment of administrative guidance under the law then in force, preserving Article 119 bis A and abuse-of-law routes.

   Separate from current legislation.

7. S7 · Journal officiel / Légifrance · 2025-02-14 · Accessed: 2026-10-27Finance Act no.2025-127, Article 96
   Passages and scope

   Act dated 14 February 2025; official publication on 15 February 2025.

   Article 96, I and II.

   Enacted beneficial-ownership and value-transfer provisions, safeguards and the 1 January 2026 effective date of the new II of Article 119 bis A.

8. S8 · French tax administration (DGFiP) · 2026-03-16 · Accessed: 2026-10-27BOI-INT-DG-20-20-20-30: withholding and tax treaties
   Passages and scope

   2026-03-16.

   Paragraphs 1–40, especially paragraph 30.

   Administrative guidance on the external framework and beneficial ownership, attributed to the French tax administration rather than a court.

9. S9 · French tax administration (DGFiP) · 2026-03-16 · Accessed: 2026-10-27BOFiP notice on external dividend arbitrage
   Passages and scope

   2026-03-16.

   Publication and effective date.

   Guidance published on 16 March 2026 for provisions applicable from 1 January 2026.

10. S10 · French Senate / Ministry of Public Action and Accounts · 2026-10-15 · Accessed: 2026-10-27Written question no.07856 and ministerial answer
    Passages and scope

    Question dated 26 February 2026; answer published on 15 October 2026.

    The ministry’s answer on artificial arrangements and abuse of law.

    Tax assessments notified are distinct from collections and are excluded from this article’s numerical model.

11. S11 · Deutscher Bundestag · 2017-06-20 · Accessed: 2026-10-27Drucksache 18/12700: fourth committee of inquiry report
    Passages and scope

    2017-06-20. Page 76: introduction, diagram and final paragraph.

    Targeted reading of this page of the 830-page report.

    German cum-ex mechanisms and multiple tax claims are distinct from the legal assessment of a French transaction.

12. S12 · France’s National Financial Prosecutor / Ministry of Justice · 2026-01-08 · Accessed: 2026-10-27PNF release on the HSBC Bank plc agreement
    Passages and scope

    2026-01-08. Page 1.

    Signed on 6 January and validated on 8 January 2026.

    HSBC Bank plc, its Paris branch and 2014–2019 transactions. An agreement is distinct from a conviction.

13. S13 · European Commission, DG TAXUD · Accessed: 2026-10-27FASTER Directive
    Passages and scope

    Evolving page, examined on 27 October 2026. Section “Why this proposal?” on taxing rights and treaties.

    Used for legitimate treaty relief and double-taxation context.

    Aggregate loss estimates on the page are excluded.

14. S14 · Conseil d’État · 2026-01-20 · Accessed: 2026-10-27Decision no.505127, ADELIBE
    Passages and scope

    20 January 2026. Paragraphs 4–8.

    The challenge became moot following withdrawal of the guidance.

    The judgment does not decide its lawfulness or a particular trade.

15. S15 · Légifrance / Code général des impôts · 2026-07-01 · Accessed: 2026-10-27Article 119 bis A: version in force since 1 July 2026
    Passages and scope

    Version in force since 1 July 2026. I, 1 and 1 bis; I, 3; II, 1 and 2.

    Current consolidated legislation, distinct from historical rulings and administrative guidance.

    Consolidation does not retroactively change the rules for past trades. Official text verified in Légifrance’s search index; direct access was unavailable during verification.