Undisclosed Work: Employer Must Prove Actual Remuneration, Not Just Duration

Imagine: you are a craftsman in Coudekerque-Branche, you hire an apprentice without declaring him for an urgent job. A few months later, URSSAF turns up and demands €15,000 in contributions on a flat-rate basis. You protest: "I only employed him for two months, and I paid him €1,500 per month, no more!" But is that enough to escape the adjustment? Not according to the Cour de cassation, which has just ruled.

This question is asked by thousands of employers every year. Undisclosed work (undeclared employment) exposes to heavy penalties: URSSAF adjustment, penalties, and even criminal prosecution. But how is the amount of contributions due calculated? And above all, how can the employer challenge it? The decision of 19 December 2013 (No. 12-27.513) provides a clear and strict answer: the proof does not stop at duration.

What does the decision specifically say? That, to prevent the flat-rate assessment of remuneration (i.e., the automatic calculation on a minimum basis), the employer must provide proof of two elements: the actual duration of employment AND the exact amount of wages paid. No half-measures. Analysis of a decision that changes the game for employers, but also for employees victims of undisclosed work.

The facts: a story that happens every day

The case began with an URSSAF inspection of an Asian restaurant company, Yi Sheng, located in a town in western France. On 13 April 2009, the recovery inspector noted the presence of four employees in a situation of undisclosed work: none of them were declared, either in the staff register or with the social security bodies. The employer, however, did not deny the facts. He produced a commercial lease signed on 16 July 2008 with the SCI des Peupliers, arguing that the employees were present on the premises well before that date, but without further details on their remuneration.

URSSAF then notified an adjustment of contributions, calculated on a flat-rate basis under Article L. 242-1-2 of the Social Security Code. This provision provides that, in the absence of proof to the contrary, remuneration is assessed on a flat-rate basis. In practice, URSSAF takes a flat-rate base (often the minimum wage or the conventional minimum) and applies it to the presumed duration of undisclosed work. Result: an amount the employer considers disproportionate.

The Yi Sheng company challenged the adjustment before the courts. Before the Rennes Court of Appeal, it argued that it had provided proof of the exact duration of employment (thanks to the commercial lease which would show that the employees were not present before 16 July 2008) and requested that the calculation be made on the basis of the wages actually paid, which it claimed to have paid in cash. But the judges were not convinced: they confirmed the adjustment. For the Cour de cassation, seized as a last resort, the employer had not proved the exact amount of wages paid. The decision was therefore dismissed, and the case was referred back to the Rennes Court of Appeal, differently composed.

The reasoning of the court — dissected

The heart of the dispute concerns Article L. 242-1-2 of the Social Security Code. This article, little known to the general public, is nevertheless a powerful tool for URSSAF. It provides that in the case of undisclosed work, the remuneration serving as the basis for calculating contributions is assessed on a flat-rate basis, unless the employer provides proof to the contrary. In other words, it is up to the employer to prove what he actually paid, not for URSSAF to discover the truth.

But what does "proof to the contrary" mean? The judges of the Cour de cassation clarify: it is not enough to demonstrate the duration of employment (for example, that the employee only worked for three months). It is also necessary to prove the exact amount of wages paid during that period. Why such a requirement? Because the flat-rate is a dissuasive penalty: if the employer could simply say "I paid €1,500 per month" without supporting evidence, the flat-rate would lose its effectiveness. URSSAF cannot verify untraceable cash payments.

The Cour de cassation thus confirms previous case law (Civ. 2e, 6 May 2010, No. 09-65.045) and even toughens it. Henceforth, the employer must produce objective elements: pay slips (even late), bank statements, payment receipts, etc. Failing this, the flat-rate adjustment is maintained. The judges rejected the argument of the Yi Sheng company, which invoked the commercial lease to limit the period of employment: this document does not prove the amount of remuneration. The decision is final: the proof must be twofold, duration AND amount.

Note that this is a social chamber of the Cour de cassation, specialised in labour and social security law. The decision is rendered under Article L. 242-1-2 of the Social Security Code, in its wording then in force. It is part of a protective trend for the rights of employees and public finances: undisclosed work is a scourge that the Court intends to sanction firmly.

What this means for you — concretely

If you are an employer, this decision is a warning. You can no longer simply say "I only employed him for two months" to reduce the adjustment. You must prove how much you paid. Worked example: an undeclared employee for 6 months, at the minimum wage (about €1,600 gross per month). URSSAF applies a flat-rate often based on the increased minimum wage (say €2,000 per month). That gives an adjustment of 6 x 2,000 = €12,000 in contributions, plus late payment penalties (up to 40%) and a penalty of €1,500 per employee (Labour Code, Article L. 8223-1). If you prove that you paid €1,500 per month (via bank statements), the adjustment drops to 6 x 1,500 = €9,000. But if you prove nothing, you remain on the flat-rate.

If you are an employee victim of undisclosed work, this decision is favourable to you. The employer cannot escape his obligations by minimising your wages. You can claim the missing contributions, and above all, obtain a flat-rate indemnity of 6 months' salary (Article L. 8223-1). Remember to keep all evidence of your work: texts, emails, photos, testimonies.

If you are a landlord in Bourbourg, you may be indirectly affected. Example: you rent a commercial property to a restaurateur who employs undeclared employees. In the event of an adjustment, URSSAF can seize the company's assets, including the business. Your rent could be compromised. Be vigilant about your tenant's good health.

Finally, for property professionals (agents, syndics), this case law reminds of the importance of verifying the social compliance of the companies you deal with. A developer who hides his employees on a site may see his property project delayed by an adjustment. Caution is advised.

Four tips to avoid this type of dispute

• Declare all your employees from the moment of hire: even for a one-week fixed-term contract, make a DPAE (Prior Declaration of Employment) via URSSAF. The cost is nil, the risk is immense.
• Keep proof of payment: pay wages by bank transfer, not cash. Keep pay slips, bank statements, employment contracts. In the event of an inspection, you will be able to demonstrate the exact amount.
• In case of an adjustment, do not deny the facts: cooperate with URSSAF. The more elements you provide, the more you can reduce the flat-rate. But expect to have to prove the amount, not just the duration.
• Consult a lawyer as soon as you receive the adjustment notice: the deadlines for challenge are short (two months). A lawyer specialising in social law can help you gather evidence and negotiate with URSSAF.

Further reading: related case law and developments

This decision is part of a consistent line of the Cour de cassation. As early as 2010, in a decision of 6 May (No. 09-65.045), the Court had ruled that the employer must prove both duration AND amount. The 2013 decision merely confirms, but clarifies that proof of the amount is essential, even if the duration is established. Another decision of 2015 (Civ. 2e, 9 April 2015, No. 14-12.876) goes in the same direction: an employer who produces employee statements but without accounting evidence does not provide proof.

The trend is therefore towards strengthening the burden of proof on the employer. The judges consider that undisclosed work is a serious fraud, and that the employer cannot benefit from it by invoking unverifiable remuneration. In the future, we can expect the courts to require even stronger evidence, such as bank statements or contribution slips. For employers, the lesson is clear: prevention is better than cure, and in the event of an inspection, it is too late to improvise justifications.

Checklist before acting

• Have I declared all my employees? Check your DPAEs and your single staff register. An omission, even unintentional, can be reclassified as undisclosed work if URSSAF considers there is intent.
• Do I have proof of wages paid? Gather pay slips, transfers, bank statements. If you pay in cash, it is almost impossible to prove.
• What is the amount of the potential adjustment? Calculate the URSSAF flat-rate (increased minimum wage x presumed duration). If you cannot prove the actual amount, this figure will be retained.
• Have I consulted a lawyer? The deadlines for appeal are two months from notification. A lawyer can help you negotiate a payment schedule or challenge the flat-rate if you have evidence.
• What should I do if I am a victim employee? Contact the labour inspectorate or a lawyer. You can obtain a flat-rate indemnity of 6 months' salary, plus reimbursement of missing contributions.

Are you in a similar situation? A 30-minute initial consultation with Maître Zakine (€45) can save you months of proceedings — and often much more. Book an appointment →