A court may base its assessment on a private expert report (expertise privée), non-judicial, carried out at the request of a single party, where documents that are not the work of the expert corroborate its content. The commercial chamber accepts that those documents may appear in an annex to the report: what counts is their origin, not their location. The accounting records of the company claiming the damage satisfy that condition.
Key points
- A non-judicial expert report commissioned by a single party may support the court's assessment, provided that its content is corroborated by documents that are not the work of the expert.
- Those corroborating documents may be annexed to the report itself: they need not be external to that document.
- Accounting records, orders, invoices and credit notes taken from the accounts of the injured company satisfy that requirement.
- In an international sale governed by the Vienna Convention of 11 April 1980, a health risk affecting the whole of the goods may characterise a lack of conformity of all the batches delivered.
- The buyer is released from giving notice of the defect where the seller knew of that defect across all the batches and itself informed the buyer of it.
A non-conforming delivery and a contested private expert report
The commercial chamber dismisses the appeal (Com., 1 April 2026, No. 24-17.785): the court could rely on a private expert report corroborated by annexed accounting documents, and all the batches delivered showed a lack of conformity. A French company processing animal raw materials had sold batches of beef to an Italian manufacturer of ready meals, which incorporated them into its products. After the horsemeat scandal came to light, the seller initially certified that the supply was exclusively bovine.
On 19 February 2013, the seller wrote to its customer that analyses had detected horsemeat in one batch. In the same letter it stated that it was placing in quarantine all supplies of Romanian origin and all products made from those raw materials. The Italian authorities then seized and destroyed all the batches manufactured from those supplies. The buyer's insurer, subrogated after payment, brought proceedings against the seller and its civil liability insurer.
The decision under appeal (CA Versailles, 30 May 2024, No. 23/04101), given following remittal after quashing (Civ. 1re, 17 May 2023, No. 22-16.290), ordered the seller's insurer to pay within the limit of the cover cap under the policy. The commercial chamber approves the lower court judges for having found a lack of conformity of all the products delivered, the health risk affecting all the meat intended for the ready meals (free translation).
Having found, in the exercise of its unfettered discretion of assessment, that [the seller] knew of the lack of conformity of all the batches sold and had informed [the buyer] of it by the letter of 19 February 2013, the court of appeal correctly inferred that [the buyer] was released from giving notice of that lack of conformity.
As regards the assessment of the damage, the commercial chamber lays down a rule of evidence that extends beyond international sales. The disputed report came from a private firm instructed by the buyer's insurer and quantified an overall damage. The accounting records, orders, invoices and credit notes annexed to it, taken from the buyer's accounts, corroborated its content.
A court may base its assessment on a non-judicial expert report carried out at the request of one of the parties, where the content of that document is corroborated by other documents, even if they are annexed to the report
What consequences for proving damage?
A company may quantify its damage with the help of an expert report that it commissioned itself, provided that it produces the documents on which the expert relied. The condition laid down concerns the origin of the documents: they must not come from the expert. Accounting records, orders, invoices and credit notes drawn up by the company satisfy that requirement, even when grouped together in an annex to the report.
The distinction is straightforward to apply. A report that merely asserts an amount, without supporting material from another source, remains fragile. A report in which each head of loss refers to an invoice, an accounting entry or a credit note allows the court to verify the figures. The opposing party retains the possibility of challenging those documents, since they are before the court.
The international sales aspect yields a separate lesson. A supplier that itself places all of its supplies in quarantine, in the name of the precautionary principle, in fact acknowledges a risk affecting the whole of the goods. That health risk, on a product intended for human consumption, may suffice to characterise the non-conformity of all the batches delivered, without a batch-by-batch demonstration.
The scope of the rule on annexed documents
The decision settles an evidential difficulty: the documents that corroborate a private expert report need not be external to the report, only their origin matters. The insurer ordered to pay argued that a court cannot base its decision exclusively on a non-judicial expert report carried out at the request of a party, and that the annexed documents are inseparable from the report. The commercial chamber, sitting in plenary formation, rejects that reasoning.
The limit remains clear. The private report is not self-sufficient: it must be corroborated, and by material of which the expert is not the author. A report accompanied only by tables or reconstructions prepared by the expert would therefore not meet that requirement. The document produced remains, in any event, open to discussion between the parties before the court.
As regards the Vienna Convention, the decision confirms the extent of the unfettered discretion of the lower court judges, who assess whether the risk affects the whole of the goods. It also confirms the informative purpose of the examination and notice formalities laid down in Articles 38, § 1, and 39, § 1: where the seller knows of the defect and informs the buyer of it, notice loses its object.
What evidentiary reflexes in commercial litigation?
A company that has its damage quantified by an expert of its own choosing must organise, from the outset of the assignment, the traceability of the source documents. The report gains strength where it identifies, head by head, the accounting and commercial documents on which it is based. Those documents must come from the company or its business partners, never from the expert. Grouping them in an annex does not weaken them, provided they are disclosed.
On the supplier's side, the information letter sent to the customer is binding. A communication announcing the quarantine of a whole category of supplies will be read as an acknowledgement of a general risk. It may also release the customer from any subsequent notice of the defect. A certificate of conformity issued without any real checks, for its part, exposes the supplier to a contradiction that is then hard to defend.
The checks to carry out before producing a private report
The first check concerns the link between each head of the report and an identified document, whether accounting or commercial. The second concerns the origin of those documents: they must come from the company or its contracting partners, not from the expert. The third concerns their actual disclosure to the opposing party. On the supplier's side, the scope of a warning letter sent to a customer is to be measured before it is sent, because it may amount to an acknowledgement of a risk affecting a whole category of products.
Frequently Asked Questions
Can an expert report commissioned by one company alone carry weight in court?
Yes. A non-judicial expert report may support the court's assessment on one condition: its content must be corroborated by documents that are not the work of the expert. The commercial chamber so held on 1 April 2026. A standalone report, with no supporting material from another source, is not enough. The document also remains open to discussion between the parties.
Can documents annexed to a private expert report be used to corroborate it?
Yes. Being placed in an annex to the report does not deprive them of corroborating value, provided they were not drawn up by the expert. In the case decided on 1 April 2026, they consisted of accounting records, orders, invoices and credit notes taken from the accounts of the injured company. The test concerns the origin of the documents, not their physical location.
Must a buyer give notice of a lack of conformity where the supplier reported the problem?
No. Where the seller knew of the lack of conformity affecting all the batches sold and informed the buyer of it, the buyer is released from giving notice. The examination and notice formalities under the Vienna Convention serve an informative purpose: they lose their object once the seller has already passed on the information. That information must, however, relate to the defect relied on.
How can a company prove the amount of commercial damage without a court-ordered expert appraisal?
Proof rests on verifiable documents: accounts, invoices, orders, credit notes, contracts and correspondence with customers. A quantification carried out by a professional chosen by the company can structure the claim, provided it relies on those documents and they are produced in the proceedings. The court assesses the value of the material before it. A figure asserted without accounting support remains, in principle, difficult to have accepted.
Does a certificate of conformity issued by a supplier protect the buyer?
A certificate of conformity is worth no more than the checks underlying it. It is useful evidence against the supplier, but it does not necessarily relieve the buyer of its own vigilance, particularly in the food sector. Conversely, a supplier issuing a certificate without any real verification exposes itself to a contradiction that is hard to defend once the defect emerges.