URSSAF is the main body responsible for collecting social security contributions in France. In a recent case, the Civil French Supreme Court addressed an important issue: can an employer submit evidence to the court that was not provided during URSSAF’s audit or the adversarial phase (the phase during which the URSSAF and the employer can exchange with each other)?
The French Supreme Court answered yes, invoking the right to a fair trial guaranteed by Article 6 § 1 of the European Convention on Human Rights (ECHR), but it limited this principle through two major exceptions related to the specific nature of the URSSAF audit procedure.
The principle
The right to a fair trial implies that an employer must be allowed to present, even belatedly, all evidence necessary to support their claims. Judges must be able to assess the facts based on all relevant material.
In this case, the employer (an association) challenged an URSSAF reassessment concerning social security contributions linked to a supplementary pension plan. It submitted, for the first time before the court, a certificate that had not been transmitted during the audit. URSSAF objected, arguing that such documents should have been provided during the audit.
The two exceptions set by the Court
The Court acknowledged that the right to evidence must be reconciled with the rules inherent to the declarative system of social contributions, which relies on after-the-fact audits. From this, two limits arise:
1. Documents expressly requested by auditors
An employer cannot produce before the court a document that was requested during the audit or adversarial phase, but not provided.
This obligation stems from Article R. 243-59 of the French Social Security Code, which requires the audited party to make available any document deemed necessary.
2. Documents the employer is legally required to keep and produce spontaneously
When the burden of proof regarding the accuracy of declarations lies with the employer, they must submit supporting documents during the audit, even without an express request. They cannot produce them for the first time before the court.
This applies in particular to:
- the rules on the deduction of professional expenses;
- flat-rate taxation (Art. R. 243-59-4 CSS);
- flat-rate assessment in cases of undeclared work (Art. L. 242-1-2 CSS);
- administrative tolerance rules excluding certain items from the contribution base (e.g. employee discounts).
Compatibility with the ECHR
These limitations are deemed compatible with Article 6 § 1 of the ECHR, since the URSSAF audit procedure already provides a period during which the employer can exchange with the URSSAF, the right to be assisted, the right to respond to the audit report within 30 days (extendable), and the obligation for the inspector to reply to the employer’s observations.
The European Court of Human Rights has itself recognized that Article 6 does not require judges to substitute themselves for the administration, but only to ensure sufficient judicial review, taking into account the safeguards offered by the administrative procedure (ECHR, Nov. 6, 2018, Ramos Nunes de Carvalho e Sá v. Portugal).
Application to this case
In this case, the audited association did not fall within either of the two exclusion categories. It was therefore entitled to submit new documents at the litigation stage.
However, the trial judges found that the certificate produced was irrelevant, as it did not concern the contract that was the subject of the reassessment. The assessment of the probative value of evidence thus remains within the trial judges’ own discretion.
Conclusion
This ruling establishes an important principle: an employer may, in principle, submit new evidence in court, even if it was not provided to URSSAF. However, caution is required.
The exceptions set by the Court serve as a reminder that withholding supporting documents during the audit is risky, since any document requested must be provided, and any document which the employer is legally obliged to produce must be submitted spontaneously.
In practice, employers are strongly advised to present all relevant documents during the audit in order to safeguard their position and reduce the risk of reassessment.
Civil French Supreme Court, September 4, 2025, N°. 22-17.437 FS-B