Proof of legal acts, secure your contracts before litigation

The rule of article 1359 of the Civil Code

Article 1359 of the Civil Code establishes the rule. A legal act involving a sum or value exceeding an amount fixed by decree must be proven in writing. This document may be a private agreement or an authentic instrument.

The amount is 1,500 euros, as Service-Public.fr. Decree No. 80-533 of July 15, 1980, as amended, sets this amount: "The sum or value referred to in Article 1359 of the Civil Code is set at 1,500 euros."

The same rule protects a signed document. It cannot be added to or contradicted except by another document, whether privately signed or authenticated, even below the legal threshold. Therefore, testimony alone is insufficient to modify a signed contract.

Splitting the claim makes no difference. A claimant whose claim exceeds the threshold cannot be exempted from submitting a written claim by restricting their demand (Article 1359).

Legal act or legal fact: the distinction that changes everything

A legal act is an expression of will intended to produce legal effects. A contract, an amendment, or a termination are examples.

A legal fact is an event: a delivery delay, a defect, damage. For a fact, proof is freely admissible. Article1358 allows any means, except where the law provides otherwise.

Let's take an example. Proving that the goods arrived three weeks late is a matter of fact: emails, delivery notes, carrier statements. Proving that the customer ordered these goods, at this price, is a matter of action.

Exceptions, when written documentation is not required

The Civil Code provides several exit strategies. These are strictly regulated.

• Impossibility of obtaining a written document: Article1360 refers to the material or moral impossibility, the custom of not establishing a written document, or its loss due to force majeure.
• Judicial confession and decisive oath: article1361 admits them in place of written document.
• The beginning of proof in writing: it must be corroborated by another means of proof (article 1361).

The party invoking these exceptions must demonstrate that their conditions are met. They therefore do not replace a document prepared in a timely manner.

The beginning of proof in writing, a document that comes from the other party

Article1362 defines it as follows: it is any written document emanating from the party contesting the act, or from their representative. This document must substantiate the allegations. An email from your client mentioning "our March order" can serve this purpose.

The crucial point lies in the origin of the written document. Article1363 states that no one can create a title for themselves. When a written document is required, your own invoice or meeting minutes alone do not prove the other party's commitment. It is their written document that counts.

The hierarchy of evidence in a table

From the strongest to the most fragile, here are the main pieces of evidence for a legal act.

When two documents conflict, and unless otherwise agreed, the judge decides. Article1368 requires him to determine, by any means, the most likely document.

What Article L. 110-3 of the Commercial Code says

With regard to merchants, commercial acts can be proven by any means, unless the law provides otherwise. This is the principle established by Article L. 110-3 of the Commercial Code.

Between merchants, the €1,500 threshold does not apply to a commercial transaction. An unsigned contract can be established by other documents.

What you can produce

The judge may receive all evidence relevant to the case. This may include the contract, even if unsigned, and the general terms and conditions.

This can also include purchase and delivery orders, emails and reminders, invoices and payments, even partial ones. Accounting practices and the conduct of the parties during the execution of the contract are also taken into account.

Free does not mean easy

The freedom of proof opens the door to all these elements. It does not, however, determine their value. The judge assesses each piece of evidence, and a message without reliable evidence of its author or date may carry little weight.

Our position is simple: free evidence is a safety net, not a method. Before looking for what the law allows you to produce, check what your file already contains.

Even when evidence is freely admissible, your invoice remains a document created by you. The judge will consider it in conjunction with other documents: purchase order, acknowledgment of receipt, and payment. Our analysis of the approval of an electronic invoice examines whether a record originating from the client can constitute a preliminary written proof.

When the freedom of proof does not apply

It has two limitations.

• The customer is not a merchant: Article L. 110-3 applies to merchants. When dealing with a private individual, a company claiming more than 1,500 euros must, in principle, provide written documentation.
• The law requires a written contract: the text makes exceptions where the law stipulates otherwise. A fixed-term employment contract, for example, must be in writing; otherwise, it is considered to be for an indefinite term.

The same logic applies to debt recovery. A solid case of evidence precedes the recovery procedure.

The same applies to proving an established business relationship, a central issue in the abrupt termination of commercial relations. Duration, volume, and regular exchanges leave traces, provided they are preserved.

What the Civil Code says about electronic writing

Article1365 broadly defines writing. It is a sequence of letters, characters, numbers, or other signs with an intelligible meaning, regardless of the medium. Paper no longer has a monopoly.

Article1366 gives electronic documents the same probative value as paper documents. Two additional conditions apply. The person from whom it originates must be duly identified. It must also be created and stored under conditions that preserve its integrity.

Article1367 deals with signatures. A signature identifies its author and signifies their consent to the obligations of the document. When electronic, it relies on a reliable identification process, which ensures its link to the document.

This reliability is presumed until proven otherwise. The signature must be created, the signatory's identity verified, and the integrity of the document preserved, under the conditions set by decree.

Simple, advanced, qualified: only one level benefits from the presumption

The decree of September 28, 2017, clarifies the text. It presumes the reliability of a process that implements a qualified electronic signature. This signature is an advanced signature, created with a qualified device and based on a qualified certificate, as defined by the eIDAS regulation.

The other signatures are not rejected outright. Article 25 of the eIDAS Regulation prohibits denying them any legal effect. It also prohibits setting them aside in court solely on the grounds that they are electronic or unqualified. But the presumption is eliminated.

What the Court of Cassation ruled on March 5, 2026

A tenant disputed having electronically signed a furnished lease for a secondary residence. The landlord produced a certificate of authenticity attached to the signature and documents issued in the tenant's name.

The Aix-en-Provence Court of Appeal ruled that the lease was enforceable against the tenant. According to the court, he had not proven either the theft of his identity papers or the use of contact information that was not his.

The Third Civil Chamber of the Court of Cassation overturned this ruling (Cass. 3e civ., March 5, 2026, No. 24-21.034). It criticized the lower court judges for failing to determine whether the process constituted a qualified electronic signature. Only such a signature establishes a presumption of reliability. This ruling was not published in the Bulletin.

The reasoning dictates an order. The judge first qualifies the signature. He only places the burden of rebutting the presumption on the contesting party afterward, if the signature is qualified.

This ruling was issued in a case concerning a lease agreement with a private individual. Between businesses, the freedom of proof allows for other means of establishing the commitment. However, when faced with a denial of an electronic signature, the judge verifies the conditions of Articles 1366 and 1367. Article287 of the Code of Civil Procedure provides for this.

A scanned signature is not an electronic signature

Pasting an image of one's signature into a PDF does not create an electronic signature. The Commercial Chamber ruled on this on March 13, 2024 (Cass. com., March 13, 2024, No. 22-16.487).

A company relied on a preliminary sales agreement bearing scanned signatures of partners. The Court of Appeal had ruled that their consent was not proven. The Court of Cassation dismissed the appeal.

The method remains valid, but it cannot be considered an electronic signature. It does not benefit from the presumption of reliability under Article 1367, paragraph 2. Anyone relying on it must establish the signatory's consent through other means.

What changes with the eIDAS 2 regulation

Regulation (EU) 2024/1183 of 11 April 2024 amends the 2014 eIDAS Regulation. Entering into force on 20 May 2024, it establishes the European digital identity wallet, which the European Commission considers to be voluntary. It complements the existing framework rather than replacing it.

Our article on remote signing of documents and contracts presents the available signing methods.

The principle of Article 1379 of the Civil Code

Article1379 establishes the principle: a reliable copy has the same probative value as the original. Its reliability is left to the judge's discretion.

The law presumes, until proven otherwise, that a copy reproducing the exact form and content of the document is reliable. Its integrity must be ensured over time according to conditions set by decree. This decree is dated December 5, 2016.

Two points to note: an enforceable or certified copy of an authentic document is considered reliable. And if the original still exists, its presentation can always be required.

The conditions of the decree of December 5, 2016

A copy is presumed reliable in two cases. Either it results from a reproduction process that causes an irreversible alteration of the copy medium, or it results from electronic reproduction that complies with the requirements of the decree.

For electronic transmission, the process must generate information related to the copy. This information specifies the context in which the copy was created, including its date. Integrity is attested by a digital fingerprint: any subsequent modification must be detectable.

This requirement is presumed to be met with a qualified electronic timestamp, seal or signature as defined in the eIDAS Regulation.

Access to reproduction and storage devices is subject to appropriate security measures. These are described in documentation kept for as long as the copy exists. Operations that maintain legibility are not considered alterations if they are recorded and result in a new digital fingerprint.

What this changes for scanning your contracts

A scan performed with a desktop scanner, without fingerprinting or traceability, does not benefit from this presumption. It remains usable. However, the judge freely assesses its reliability.

This assessment can be harsh. A copy without fingerprints, without traceability, and without any other corroborating evidence risks being rejected.

Our advice remains the same: keep the original paper copies. If you digitize your archives, do so using a process that complies with the decree and keep the documentation.

Choose the writing format according to the issue at hand

A standard purchase order does not require the same level of proof as a shareholders' agreement or a guarantee. For a high-stakes commitment, a private agreement countersigned by lawyers serves as proof of the writing and signatures of the parties (Article 1374).

This document is exempt from any handwritten entries required by law. The forgery procedure applies to it.

Sign at the correct level and keep the evidence file

For sensitive contracts, prioritize qualified electronic signatures: only they benefit from a presumption of reliability. For all others, retain the proof file from the service provider.

The choice hinges on two questions: what is at stake, and who could contest it? For a routine order between two companies, a simple signature and its supporting documentation may suffice, as evidence is freely admissible between merchants.

For a pact, a long-term commitment or a contract with a non-merchant, the qualified signature or the act countersigned by lawyers limits the debate.

Keep together the signed document, unaltered after signing, and the proof file provided by the service provider. Add the signatories' identification details. Attach proof of the signatory's authority, such as a company registration certificate (Kbis extract) or a power of attorney.

Preserve over time

Article 1366 requires that an electronic document be created and stored under conditions that preserve its integrity. A file stored without access control or backup weakens the evidence.

Accounting documents and their supporting documentation must be kept for ten years (Article L. 123-22 of the French Commercial Code). Obligations arising from commercial transactions, whether between merchants or with non-merchants, are generally subject to a five-year statute of limitations (Article L. 110-4). Keep the contract and its supporting documents during its execution, and then at least for this period.

Establish a convention of evidence

The parties may agree on how they will prove their commitments. Article1356 validates contracts based on evidence when they concern rights over which the parties have free disposal.

This freedom has limits. Such a contract cannot contradict an irrebuttable presumption established by law, nor can it alter the weight given to an admission or oath. It also cannot establish an irrebuttable presumption in favor of one party.

In your contracts, the clause may specify the accepted methods of communication, the validity of electronic signatures, and notification addresses. In a standard form contract, a non-negotiable clause that creates a significant imbalance is deemed unwritten (Article 1171). A clause regarding evidence that is too favorable to one of the contracting parties may also be deemed unwritten.

Confirm in writing what has been said

After a meeting or call, send a summary email. This email establishes the date and content of what was agreed upon. When dealing with a non-business party, it originates from you, and Article 1363 reminds us that no one can create a legal title for themselves. Between businesses, the judge will assess it in conjunction with other relevant documents.

What matters is the other party's response. A written agreement, even a brief one, is a document originating from the party against whom you are presenting it (Article 1362). Silence, however, does not constitute acceptance, unless otherwise provided by law, custom, business practices, or specific circumstances (Article 1120).

For a firm recovery, a formal notice drafted by a lawyer can become a decisive piece of evidence in court.

The three errors found in evidence files

• To believe that free proof eliminates the need to preserve evidence. The freedom of proof only helps those who have retained something to produce.
• Replace the signature with a scan or a photo. An image of a signature does not identify its author and does not prove their consent.
• Leaving contracts in an email without a backup. A modifiable or lost file no longer guarantees its integrity, as required by Article 1366.

The turnaround of December 2023

A salesperson records a call. An employer produces a private message exchange between an employee. In both cases, the evidence was obtained without the other party's knowledge.

Until then, civil case law had, in principle, excluded evidence obtained unfairly, such as the recording of a conversation without the knowledge of its author.

On December 22, 2023, the plenary assembly of the Court of Cassation changed its position (nos. 20-20.648 and 21-11.330). In a civil trial, the illegality or unfairness of evidence no longer necessarily leads to its exclusion from the proceedings.

The two conditions set by the Court of Cassation

The judge must assess whether the evidence compromises the fairness of the proceedings. They must weigh the right to evidence against opposing rights, such as the right to privacy.

The right to evidence can justify the production of elements that infringe on other rights, under two conditions:

• this production must be essential to the exercise of the right to evidence;
• The infringement must be strictly proportionate to the objective pursued.

What the two cases judged that day show

In the first case, an employer had recorded, without an employee's knowledge, interviews, including the interview prior to his dismissal. The Court of Appeal had excluded these recordings from the case. The Court of Cassation overturned the decision and remanded the case: the two conditions mentioned above must be verified.

In the second case, an employee had a private conversation on his Facebook account's messaging service. A colleague read it at work and forwarded it to the employer. This exchange could not be grounds for disciplinary dismissal. A private conversation not intended for public consumption does not constitute a breach of the employment contract. The appeal is dismissed, as the argument based on the right to evidence is ineffective.

This solution is valid before a civil judge. It does not eliminate the criminal risk, as provided for in Article226-1 of the Penal Code.

This law criminalizes violations of privacy. Such violations can result from the recording, without the speaker's consent, of words spoken privately or confidentially. The penalty is one year of imprisonment and a fine of €45,000.

The lesson is clear. This option remains a last resort, subject to judicial review. Fair evidence is preferable: a signed report, a confirmation email, a written agreement to record the exchange.

Remember these three points. Above €1,500, written proof is essential. Between businesses, everything can be proven, but everything is open to discussion. Finally, a scan is not the same as an electronic signature, and the signature itself is examined according to its level of security.

The work begins beforehand: the format of the document, the level of signature, its storage, and confirmed exchanges. Our lawyers assist companies with contracts, distribution, and franchising, from drafting the contract to any potential litigation.