A recalculation has revealed an overpayment, and the payroll confirms the error. Accounting has identified a specific payment, but these observations do not yet fully explain what remains to be reimbursed. The file must clearly link each claimed amount to a specific period, establishment, applicable rule, and payment. It also needs to trace any corrections already made. A previous article examined the deadlines and limitations of the reimbursement action, while this one focuses on the practical steps needed to turn a detected discrepancy into a documented and verifiable request. To claim overpaid contributions, the principle of refunding overpaid amounts is outlined in Article 1302 of the Civil Code. Article 1353 requires the person claiming to prove the execution of an obligation. For social security contributions and family allowances, these principles are combined with the specific regime outlined in Article L243-6 of the Social Security Code. To prepare a request, three key questions must be answered: what did the company pay? What should it have paid? Why does the difference constitute an overpayment? This demonstration concerns the company requesting a refund and does not exempt URSSAF from justifying a correction when it initiates one. A parameter configuration error is an indicator. Matching the documents allows the consequences to be established. The seven categories of documents to gather include DSNs actually transmitted, corrections, and reports from the organizations, detailed payroll extractions and history of parameters, payments, accounting entries, and URSSAF account movements, justifications specific to the claimed treatment, detailed recalculation tables, history of credits, allocations, and reimbursements, and claims, decisions, and proof of receipt. These documents help establish what was declared for the relevant periods, how the bases, rates, and reductions were formed, what was paid and to which debt each payment was allocated, why the rate, reduction, or exclusion invoked are applicable, how the requested amount is determined, what has already been recovered and what remains to be processed, and the steps already taken, any potential obstacles, and the deadlines. In practice, before changing a service provider or payroll software, retrieve the archives and verify that they are readable. Preserve the original files and work on identified copies. Access to a history should not depend on maintaining an old subscription. Moving from the calculated discrepancy to the remaining amount to claim involves establishing the initial contribution, the contribution at the notified rate, the initial difference, and the credit relating to this difference already used. The file must explain the remaining difference as clearly as the initial difference. Requesting the already used credit again would amount to counting the same correction twice. Conversely, a correction recorded in the software does not prove its transmission or processing by the organization. It is necessary to distinguish what has been corrected in payroll, declared, admitted, credited to the account, allocated, or reimbursed. The detected amount, the requested amount, and the amount actually recovered must be tracked separately. If the overpayment includes employee contributions, they must be separated from employer contributions. The employer is the contributor who submits the request to the organization, including for precomputed contributions. The handling of amounts owed to employees must be examined separately; the entire reimbursement should not be presented as an employer saving. Constructing a file that a third party can verify involves having one line per establishment, period, and reason, with a detailed breakdown per employee when the calculation requires it. If the provision includes an annual adjustment, examining only one month may be insufficient. For each line, show the initial amount, the corrected amount, the adjustments already taken into account, and the references to the supporting documents. The hypotheses still to be confirmed should remain visible. A simple numbering facilitates reading: P01 for the notification, P02 for the base extraction, P03 for the declarations, P04 for the payments and their allocation, P05 for the previous credit. The calculation refers to these documents. This classification is a practical recommendation without any particular legal formality. The test is concrete: can a reader who has not participated in the audit redo the calculation without asking the author to explain each cell? Before sending, prepare a summary indicating the company and the establishments involved, the contributions, periods, and payments concerned, the legal basis and the facts justifying its application, the requested amount or the elements allowing it to be determined, and the list of attached documents and previous steps taken. The request must clearly express the refund sought. A simple file transmission or a request for an explanation does not provide the same level of security. Preparing the documents without letting the deadlines expire involves first verifying the payment dates and the history of decisions. It begins as soon as the discrepancy is detected. In principle, the refund request is subject to a three-year statute of limitations from the payment of the contributions. The late discovery of an error does not suffice to push back this starting point. However, the specific rules and the causes of suspension or interruption must be examined according to the origin of the overpayment (Article L243-6, I; Cass. 2e civ., 6 April 2023, n° 21-19.111). A final calculation is not always necessary to interrupt the statute of limitations. In its ruling of 28 May 2014, the Court of Cassation recognized this effect to a request containing all the elements allowing the determination of the overpayment. The letter specified the basis, the period, and the establishments, with supporting documents. This solution does not allow for a general reservation while waiting for a future audit (Cass. 2e civ., 28 May 2014, n° 13-17.758). In practice, keep the request, its annexes, and proof of its receipt together. A document prepared internally is not necessarily a document transmitted. It is also necessary to check if the contributions have already been subject to a definitive adjustment. A non-contested notice within the deadlines may hinder their reimbursement. This limitation concerns the contributions subject to the adjustment; it does not close all the company's requests indiscriminately (Cass. 2e civ., 18 February 2021, n° 19-24.513). If an URSSAF audit is ongoing, produce the justifications at the right time. The file can be used to present a credit in the audit exchanges. The detailed observations made within the response period to the letter of observations require a reasoned response. This obligation does not guarantee the acceptance of the credit or the automatic expansion of the investigations to any new subject (Article R243-59, III). The possibility of acting before the final calculation should not be confused with the possibility of producing evidence late. In disputes over adjustments, the Court of Cassation specifically prohibits presenting for the first time to the judge a document explicitly requested during the audit or the adversarial phase. When the proof of the conformity of the declared information is the responsibility of the contributor, the justifications must also be produced during these phases (Cass. 2e civ., 4 September 2025, n° 22-17.437). However, there is no general prohibition on producing a new document in court. The court confirmed this by admitting contracts that had not been requested during the audit and whose conformity was not to be proven by the contributor (Cass. 2e civ., 13 May 2026, n° 22-12.881). In practice, keep a record of the requested documents, their transmission date, and the point they justify. Do not wait for a potential appeal to constitute the proof of a claimed provision. If all the points examined lead to a credit balance, the organization must notify it and reimburse it within the following month. This deadline specific to the audit balance does not start from the first submission of the justifications (Article R243-59, IV). A targeted audit becomes useful when a single documented discrepancy, related to payments, may call for a limited correction. The audit becomes more interesting when the error spans multiple establishments or fiscal years, when the histories come from multiple service providers, or when the right to a reduction remains to be established. Its scope must allow the examination of both favorable and unfavorable discrepancies. Their correlation illuminates the company's decision; it does not, by itself, authorize a compensation between claims and debts. An accepted reimbursement with a reservation for a subsequent audit does not protect against an adjustment after verification of the provision's conditions. The Court of Cassation reminded this on 4 December 2025. This reservation justifies keeping the file that supported the request, even after receiving the funds (Cass. 2e civ., 4 December 2025, n° 23-18.086). To frame an audit, request a deliverable that distinguishes documented amounts, points still dependent on a document, procedural obstacles, and corrections to be organized. Each observation must lead to an action, a responsible party, and a deadline. The first meeting between payroll, finance, and the advisory team can start from a common table: one line per discrepancy, the available documents, the missing documents, and the next decision. It is on this basis that the company can assess what it is able to claim and the work necessary to achieve it. Cited texts and decisions verified on 25 September 2026.