French Supreme Court (Cour de cassation), Commercial, Financial and Economic Chamber, 6 May 2026, No. 25-14.501 (Cassation)
🔑 Key Takeaways
- The French Supreme Court quashes the judgment of the Colmar Court of Appeal (cour d’appel) (5 March 2025) which had annulled a guarantee of €78,000 for an irregular handwritten note.
- The protective formalism of former Article L. 341-2 of the Consumer Code (code de la consommation) requires the guarantor to write the note in his own hand and to sign below it: here, the note had been written by a third party and the signature placed above it.
- The Court applies the principle fraus omnia corrumpit: a guarantor who knowingly misuses the formalism to defeat the claim for payment cannot invoke the nullity of his undertaking.
- The lower courts must now look concretely for the guarantor’s fraudulent intent, and not merely record the material irregularity.
- The case is remitted to the Metz Court of Appeal; the guarantor is ordered to pay the costs and €3,000 under Article 700 of the Code of Civil Procedure.
- The burden of proving fraud rests on the bank that alleges it: a mere material irregularity is not enough to establish bad faith.
Contents ▼
- What happened in this guarantee case?
- What does the handwritten note formalism require?
- Does this formalism still exist today?
- Why did the French Supreme Court overturn the annulment?
- What does fraus omnia corrumpit mean?
- What criticisms can be made of this decision?
- Turning fraud against the protected party: a shift?
- Who bears the burden of proving fraud?
- Is the bank’s negligence ignored?
- What to remember if you are a guarantor?
- FAQ: Frequently Asked Questions
What happened in this guarantee case?
The case has its roots in a conventional bank financing transaction. On 19 December 2011, a bank granted a civil engineering company an overdraft facility (facilité de caisse) of €130,000, usable on its current account. An overdraft facility is an authorisation to be overdrawn: the bank allows the company to run its account in debit, within an agreed limit, to absorb cash-flow timing gaps.
As is almost always the case with this type of facility, the bank required a personal guarantee. On 8 February 2012, the company’s manager stood as joint and several guarantor (caution solidaire), up to €78,000, securing all of the company’s commitments. By signing this deed, he undertook to pay the company’s debt if it failed to do so.
The risk materialised: the company was placed into administration (redressement judiciaire), then into liquidation (liquidation judiciaire). The bank, no longer able to expect much from the failed company, logically turned to the guarantor and sued him for payment. The guarantor then pulled out a classic but formidable defence: the nullity of his own undertaking, on account of an irregularity in the statutory handwritten note.
And the irregularity is, on paper, real. Two anomalies affect the deed: first, the handwritten note was not written by the guarantor in his own hand, having apparently been copied by a third party (his secretary); second, the guarantor’s signature is positioned above the handwritten note, and not below it as the law requires. To flag this inversion, a bracket had been placed in front of the handwritten note, and an arrow led from this bracket to the signature.
The Colmar Court of Appeal, on 5 March 2025, found in favour of the guarantor: it noted that the note had not been written in the guarantor’s hand and that the signature was wrongly placed, and inferred from this that the guarantee was void. The bank, seeing its security collapse, appealed on points of law. And it succeeded.
What does the handwritten note formalism require?
To understand what is at stake, we need to go back to the applicable text. As the deed was entered into in 2012, it is former Article L. 341-2 of the Consumer Code, in its wording prior to the Ordinance of 14 March 2016, that governs the validity of the note.
This is a precise statutory formula that any individual standing as guarantor to a professional creditor must copy out by hand, in his own writing, just before his signature. Under former Article L. 341-2 of the Consumer Code, this note had to be reproduced word for word, “and only that”: “By standing as guarantor for X…, up to the sum of… covering payment of the principal, interest and, where applicable, penalties or late-payment interest, and for a period of…, I undertake to repay the lender the sums owed out of my income and my assets if X… does not itself satisfy them.”
This formalism is not a mere formality. Its purpose is protective: by requiring the guarantor to write out the exact extent of his undertaking himself, by hand, the legislature aims to ensure that he fully grasps what he is signing. Copying out “I undertake to repay… out of my income and my assets” forces an awareness that a simple signature at the foot of a pre-printed form does not guarantee. The sanction for the irregularity is severe: nullity of the undertaking, that is, its outright annihilation.
The two cardinal requirements are therefore: personal handwriting of the note by the guarantor, and its position, immediately above the signature, the signature having to “follow” the note and therefore appear below it. On both points, the disputed deed was objectively deficient.
Does this formalism still exist today?
Yes, but in a relaxed form. Former Article L. 341-2 was first recodified as Article L. 331-1 of the Consumer Code. Then, the Ordinance of 15 September 2021 reforming the law of security interests (droit des sûretés) transferred the subject to the Civil Code (code civil): it is now Article 2297 of the Civil Code that governs the note of an individual guarantor. Above all, the legislature abandoned the requirement of a sacramental formula reproduced “identically”. The guarantor must now affix a note expressing that he undertakes to pay, up to an amount in principal and ancillary sums, but without a model imposed word for word.
For guarantees entered into before 1 January 2022, however, the former rigid formalism continues to apply, which explains why this 2012 case is still being litigated in 2026. A large part of current litigation concerns precisely these older deeds, where the slightest missing comma could result in nullity.
Why did the French Supreme Court overturn the annulment of the guarantee?
The French Supreme Court does not deny the irregularity. It does not say that a note written by a third party or a wrongly placed signature would be valid. It shifts the debate to a different ground: the guarantor’s good faith.
Citing former Article L. 341-2 of the Consumer Code and the principle fraus omnia corrumpit, the Commercial Chamber states that “fraud committed by the guarantor in drafting the statutory handwritten notes, prescribed on pain of nullity of the guarantee by that provision, prevents the guarantor from relying on those provisions”.
This Latin maxim means “fraud corrupts everything”. It is a general principle of French law under which a person cannot derive any advantage from a fraud he has himself committed. Applied here: a guarantor who deliberately arranged the irregularity of the handwritten note, with the aim of being able to invoke nullity later and escape payment, cannot rely on that nullity.
What does fraus omnia corrumpit mean in this case?
The criticism levelled at the Colmar Court of Appeal is a lack of legal basis (défaut de base légale): it stopped at the material finding of the irregularity (note not written by the guarantor, signature above it) without examining, “as it was invited to do”, whether the guarantor had not “knowingly misused the protective formalism” whose benefit he was claiming. In other words, the Court of Appeal should have asked whether the manager had not deliberately had the note written by his secretary and placed his signature in the wrong spot, knowing that this would create a ground of nullity that he could draw on the day the bank called on him to pay.
The Court’s logic is as follows: the formalism of Article L. 341-2 exists to protect the guarantor. It cannot be tolerated that a guarantor turns it into an offensive weapon against the creditor, knowingly arranging a ground of nullity for himself. The shield must not become a sword.
⚙️ The Court’s three-step reasoning
↓
2️⃣ But if the guarantor knowingly brought about this irregularity to escape payment → fraud.
↓
3️⃣ Fraus omnia corrumpit → the fraudulent guarantor can no longer invoke nullity → the undertaking stands.
Procedural consequence: the Colmar judgment is quashed in its entirety, the case is remitted to the Metz Court of Appeal, and the guarantor is ordered to pay the costs and to pay the bank €3,000 under Article 700 of the Code of Civil Procedure. The court of remittal will therefore have to decide the question of fact left open: was there, or was there not, a fraudulent manoeuvre?
What criticisms can be made of this decision?
The solution is consistent with the spirit of the principle fraus omnia corrumpit and hard to challenge in principle: no one should be able to profit from his own wrongdoing. Nevertheless, from the standpoint of protecting guarantors, whom our firm habitually defends against banking institutions, this decision calls for several serious reservations, which map out as many lines of defence for the future.
Turning fraud against the protected party: a shift?
The first difficulty lies in the very nature of the formalism at issue. The handwritten note was designed as a protection for the guarantor, the party presumed to be weak. By accepting that this formalism can be neutralised by the fraud of its beneficiary, the Court opens a breach whose contours are uncertain. Where does mere negligence, which should never deprive the guarantor of statutory protection, end, and where does fraud begin?
The practical risk is real: faced with any claim for nullity based on a defective handwritten note, banks will now be tempted to systematically plead fraus omnia corrumpit, arguing that the guarantor “knew” and “let it happen”. If the lower courts accepted this argument too readily, the protective formalism would lose much of its effectiveness: it would suffice to allege bad faith to empty the sanction of its substance. The vigilance of the courts of remittal will therefore be decisive in ensuring that the fraud exception remains confined to genuinely established cases.
Who bears the burden of proving fraud?
This is undoubtedly the most important point for the defence of guarantors, and the judgment, read carefully, leaves them a weighty argument. The Court nowhere says that the material irregularity amounts to a presumption of fraud. It requires an inquiry into fraudulent intent: the court of remittal will have to establish, by concrete evidence, that the guarantor acted “knowingly”, with the aim of misusing the formalism.
Yet fraud is not presumed: it is proved. And the burden of that proof rests on the party who invokes it, that is, the bank. The mere fact that a third party physically wrote the note, or that the signature is wrongly placed, does not in itself establish an intention to harm. These anomalies may just as well result from clumsiness, from ignorance of the legal requirements, or from the practical conditions of the signing, all perfectly innocent explanations. A diligent guarantor will therefore be able to argue that the bank fails to prove a genuine manoeuvre, and that the doubt must benefit him.
🛡️ The line of defence to remember
≠ automatically → Established fraud
The bank must prove the guarantor’s intention to arrange a nullity for himself. Failing that, the nullity stands.
Is the bank’s negligence ignored?
One last angle deserves emphasis, as the judgment says nothing about it. The guarantee was received by a professional creditor: a bank, well versed in drafting this type of deed. How could a credit institution accept, and keep for years, a deed whose handwritten note was so irregular (written by a third party, signature inverted, a bracket and an arrow patching over the error)? The credit professional plainly had the means to detect and refuse this irregularity at the time of signing.
There is an asymmetry here that the decision does not address. The Court scrutinises the guarantor’s bad faith, but remains silent on the diligence, or lack of diligence, of the bank that collected a manifestly defective deed, before now taking advantage of it by denouncing the “fraud” of its counterparty. One may wonder: if the irregularity was so conspicuous (to the point of being flagged by a bracket and an arrow on the deed itself), the argument of the guarantor’s “hidden” fraud loses force, and that of the professional creditor’s carelessness gains relevance. This is ground that guarantors will do well to occupy.
What to remember if you are a guarantor?
This decision is not a general condemnation of guarantors: it penalises a specific scenario, that of a deliberate manoeuvre. But it sends a clear signal, in both directions.
✅ To secure a guarantee undertaking
✍️ Write the note yourself, in full, in your own hand.
📍 Sign below the note, never above it or beside it.
🚫 Never delegate the writing of the note to a third party (secretary, spouse, accountant).
📑 Keep a copy of the signed deed.
⚖️ If a bank demands payment from you
🔍 Have the deed examined: an irregular note remains a ground of nullity.
🧾 If the bank alleges fraud, demand that it prove your intention; the irregularity alone is not enough.
📊 Also check the proportionality of the undertaking to your income and assets, and compliance with the duty to warn (devoir de mise en garde).
Beyond the formalism alone, remember that a guarantor often has several cumulative lines of defence: the manifest disproportion of the undertaking relative to his assets and income (which can render it unenforceable), the bank’s breach of its duty to warn where the undertaking was unsuitable, or compliance with the annual information obligations owed to the guarantor. Nullity based on the handwritten note is only one lever among others, and, after this judgment, a lever to be handled with a solid file.
Conclusion
By this judgment of 6 May 2026, the Commercial Chamber confirms the application of the principle fraus omnia corrumpit to the protective formalism of guarantees: a guarantor who knowingly arranges a ground of nullity for himself will not be able to invoke it. The solution is legally defensible and morally intuitive: one does not profit from one’s own fraud.
But it should not be read as a blank cheque for banks. Three safeguards remain, and they will make the difference in future cases: the fraud must be established, and not inferred from the irregularity alone; its proof rests on the bank that alleges it; and the argument runs up against the professional creditor’s own negligence in accepting a manifestly defective deed. For guarantors and their advisers, the challenge now is not to let the fraud exception become commonplace. Well argued, the defence remains fully open.
Our firm, dedicated to banking law, assists guarantors, borrowers and customers in challenging their undertakings and defending themselves against credit institutions. An analysis of your guarantee deed makes it possible to identify all the grounds available: formal irregularity, disproportion, failure to warn.
