Reviewing payroll before closing: the anti-adjustment checklist

Quick answer. Before validating the monthly DSN, a consistency review of payslips limits the risk of an adjustment: check ceilings (monthly social security ceiling of EUR 4,005 in 2026), contribution rates, bases, the general reduction, the net social amount and the match with cumulative figures. URSSAF can audit the last 3 calendar years plus the current year (up to 5 years in case of concealed work). A structured monthly review costs a few minutes; an adjustment runs into thousands of euros.

The monthly DSN has become the tipping point of payroll: once transmitted, it feeds URSSAF, the pension funds, France Travail and the tax authorities. Correcting afterwards is possible, but heavy and it leaves a trace. The right reflex is to review before validating, while the payslips are still in draft.

In 2026, two developments sharpen the stakes. First, the net social amount, a mandatory payslip mention since 1 July 2023 and declared in the DSN since 1 January 2024, is subject to a consistency check by URSSAF. Second, the general roll-out of dematerialised document audits makes inconsistencies more visible. A rigorous consistency review, month after month, is one of the strongest safeguards against a cold adjustment.

Reviewing consistency does not mean redoing payroll: it means checking that the aggregates are plausible and concordant. Three levels of control complement each other:

1. The payslip check: plausibility of the gross, the rates, the net, the ceilings applied.
2. The inter-payslip check: consistency from one month to the next (a gross that doubles without explanation, a contribution that disappears).
3. The DSN check: concordance between the declared cumulative figures and the sum of the payslips.

This work fits into the monthly payroll cycle and extends the management of payroll variables: the variables entered at the start of the cycle are checked at the end of it.

Here are the points to go through before validating the month's payroll. Each block corresponds to a family of adjustment risks.

This checklist is complemented by a finer review when setting up a file, as in the first payslip checklist.

The net social amount is the gross remuneration reduced by the social contributions and levies borne by the employee. It is the reference used by the authorities to calculate the activity bonus and the RSA. Since 1 January 2024, it has been declared in the DSN and URSSAF checks its consistency.

In practice, three checks are needed:

• The net social amount shown on the payslip must match the net social amount declared in the DSN.
• The items included in the net social amount (bonuses, benefits in kind, allowances) must be correctly configured: an omission distorts the employee's rights.
• The annual cumulative figures must progress consistently, without unexplained breaks.

A discrepancy on the net social amount is today one of the first anomalies flagged by URSSAF, because it is immediately visible in the declared data.

URSSAF can audit and adjust the contributions due for the 3 calendar years preceding the year of the audit notice, plus the current year. For concealed work, this period is extended to 5 years. Contributions are time-barred after 3 years from the end of the calendar year for which they are due (article L244-3 of the Social Security Code).

During the audit, the limitation period is suspended for the duration of the adversarial phase: the employer has a deadline to respond to the observations before recovery. A well-kept payroll file — archived payslips, exemption supporting documents, applied collective agreements — turns an audit into a simple formality. Keeping payslips is, moreover, a separate obligation (5 years for payslips, under the Labour Code).

• Entries and exits during the month: the ceiling must be prorated; a full ceiling applied to an employee who arrived on the 20th of the month is a frequent error.
• Progressive or annual ceiling regularisation: depending on the method chosen, gaps are caught up at year-end; the December review is therefore specific.
• Benefits in kind: vehicle, housing, meals, digital tools — often forgotten in the base, they are a classic adjustment target.
• Overtime: increase, employee exemption and flat-rate employer deduction must be consistent with one another.

• An outdated AT-MP rate. The rate notified each year by the Carsat must be entered: an old rate generates a systematic gap.
• A mis-recalculated general reduction. The annual regularisation of the general reduction is a major source of gaps; an unregularised monthly calculation leads to over- or under-payments.
• An inconsistent net social amount. The first anomaly visible in the DSN: a priority to check.
• The absence of an audit trail. Without archived supporting documents, the employer cannot defend themselves during an audit. Traceability is as important as the calculation.

A services SME recently entrusted us with its payroll after an adjustment of several tens of thousands of euros: for three years, benefits in kind (company cars) had been correctly paid but never included in the contribution base. The error, invisible on an isolated payslip, repeated every month. A simple monthly consistency review would have caught it from the first payslip.

The lesson is constant: payroll risk is almost never a spectacular one-off error, but a small systematic error that repeats. That is precisely what a pre-closing consistency review is designed to catch. For a small business bringing payroll in-house, formalising this checklist is a minimal investment against the risk, just like optimising the result before the accounting close on the tax side. As an expert-comptable registered with the Ordre and a statutory auditor, we regularly supervise these reviews for Paris-based directors.

Hayot Expertise tip. Build a fixed monthly checklist and run it systematically before validating the DSN, starting with the net social amount and the ceilings. Archive each month the supporting documents for exemptions and the AT-MP rate: this is your best defence in case of an audit. If your headcount exceeds about ten employees or your collective agreement is complex, have the review supervised by your accountant once a quarter.