Challenging a URSSAF Reassessment for a Client: The Roles of the Accountant and the Lawyer
Challenging a URSSAF reassessment is not an accounting exercise: it is a legal procedure with strict deadlines, in which the accountant (expert-comptable) and the lawyer each intervene on their own ground. The accountant masters the figures and the calculation bases; the lawyer drives the litigation strategy. The outcome hinges on the coordination of the two — and it begins with the letter of observations.
This article is part of our page Accountants: your partner lawyer in employment law and complements our resource URSSAF Audit: The Employer’s Guide.
The Timeline of a Challenge, Step by Step
The audit is governed by Article R.243-59 of the French Social Security Code. Once the verifications are complete, the inspector sends a letter of observations (lettre d’observations) detailing the intended heads of reassessment. This opens the contradictory period (période contradictoire): the employer may respond, contest, and produce evidence. Then comes the formal notice (mise en demeure). To challenge it, you first refer the matter to the URSSAF’s Amicable Appeals Board (Commission de recours amiable, or CRA), then, if it is rejected, to the social division of the judicial court (pôle social du tribunal judiciaire).
Each of these stages is bound by a deadline. Missing them means losing rights — permanently.
Who Does What
The Letter of Observations: The Work Begins Together
This is the key moment. The accountant provides the documents, verifies the calculation bases, and quantifies the actual impact of each head of reassessment. The lawyer analyses the legal soundness of each head: is it well-founded in law? Is the calculation method correct? Is the supporting evidence probative? A response targeting the weakest heads, rather than a blanket challenge, is often decisive.
The Contradictory Period: Never Simply Endure It
Too many employers respond alone, under time pressure, or fail to respond at all. This is a mistake: it is the last window to strike down a head of reassessment before it becomes final. Extending it where possible, securing any tacit agreement, and documenting every objection: these are all litigation reflexes.
The CRA, Then the Social Division: The Lawyer’s Territory
After the formal notice, the challenge enters its judicial phase. The referral to the CRA must be complete and well argued; where applicable, the referral to the social division is subject to rules on time limits, jurisdiction, and the burden of proof. This is an act of defence that falls to the lawyer.
Deadlines and Limitation: The Heart of the Case
The reassessment covers, in principle, the last three years (the current year and the three preceding calendar years), extended to five years in cases of undeclared work (Article L.244-3 of the French Social Security Code). Certain acts suspend or interrupt this limitation period. Keeping a precise calendar — the dates of the notice, the letter of observations, and the formal notice — regularly makes it possible to set aside part of the reassessment on grounds of limitation or time-barring.
Securing Your Position Before the Audit: The Payroll Audit
The best litigation is the one you avoid. A payroll audit maps the risks on sensitive schemes — bonuses, benefits in kind, professional expenses, the standard deduction for professional expenses (DFS), and exemptions. This is work in which the accountant and the lawyer are naturally complementary: one knows the payroll configuration and history, the other reads the litigation risk.
The DAIRIA Perspective
Our URSSAF practice is led by a former URSSAF litigation inspector. We do not guess how URSSAF reasons: we did it from the inside for more than ten years. For an accountant, this is the assurance of a partner who knows where the weak heads of reassessment lie — and where the room for manoeuvre is.
To go further: Accountants: your partner lawyer in employment law.