In short:
- The DSN is an online filing, produced every month from payroll software, used to pay social contributions and inform social protection bodies in France.
- A business with fewer than 50 employees submits its DSN by the 15th of the month following the paid work period, and pays its contributions on the same date.
- Sick leave, early returns to work and contract terminations are reported through an event DSN within 5 working days.
- A late DSN costs €60 per employee per month of delay, according to the Service Public Entreprendre page checked on 4 May 2026.
What is the DSN?
The DSN, or déclaration sociale nominative (nominative social declaration), is an online filing that every employer in France must produce each month. According to Service Public Entreprendre page F34059 (in French, checked on 4 May 2026, consulted on 5 November 2026), it is generated from payroll software and sends information on each employee in a single, automated way.
All businesses with employees are concerned, whatever their size. A small business hiring its first employee therefore enters the system from its first payroll.
The DSN contains two types of information. On one side, payroll data for each employee. On the other, events affecting their periods of activity: sick leave, illness, maternity, paternity, end of contract.
One DSN per establishment
The DSN is filed per Siret number, meaning per establishment, not per Siren number. A business with several establishments therefore produces as many DSNs as it has establishments.
What the DSN does for the employer
The DSN performs two functions, according to Service Public Entreprendre:
- Calculating and paying social contributions.
- Automatically transmitting employee information to social protection bodies: CPAM (health insurance), Urssaf, Agirc-Arrco (supplementary pension), supplementary health insurers and France Travail (the public employment service).
It also includes income tax withholding at source. The employer withholds tax every month alongside contributions, then pays it over to the business tax office.
The filings the DSN replaces
The DSN centralises many filings that used to be made separately. Among those listed on the official page:
| Area | Examples of formalities handled through the DSN |
|---|---|
| Salaries and contributions | Contribution summary slip, former annual DADS-U filing |
| Tax | Withholding tax data |
| Sickness and occupational risks | Salary certificate for daily sickness allowances |
| Employment and contract end | Employer certificate for France Travail |
| Training | Collection of the apprenticeship tax, funding of the personal training account (CPF) |
| Pensions | Updating pension accounts across all schemes |
For a small business, this saves time: a single monthly filing replaces a series of forms sent to different bodies.
The DSN calendar for a small business
The periodic DSN is submitted once a month, during the month following the paid employment period. The deadline depends on headcount.
| Headcount | DSN deadline | Contribution payment deadline (general scheme) |
|---|---|---|
| Fewer than 50 employees | The 15th of the month following the work period | The 15th of month M+1, whatever the salary payment date |
| Fewer than 11 employees with the quarterly option | The 15th of the month following the work period | The 15th of the first month of the following quarter |
| 50 employees or more | The 5th of the month following the work period | The 5th or the 15th of month M+1 depending on the salary payment date |
If the deadline falls on a public holiday or non-working day, it moves to the next working day. The rates and ceilings applied are those of the period of activity, even if the salary is paid the following month.
For businesses under the agricultural scheme, contribution payment dates follow their own calendar, detailed on the same page.
Event DSNs
Between two monthly DSNs, some events must be reported without waiting. The event DSN (DSN de signalement d’événement) is submitted within the 5 working days following the event.
The events concerned are:
- Sick leave: illness, maternity, paternity, etc.
- An early return to work, when the employee returns before the planned end date of their leave.
- The end of an employment contract, whatever the reason for leaving.
These reports have a direct effect for the employee. The salary certificate sent in case of sick leave, for example, triggers the payment of daily allowances, and the end-of-contract certificate is used by France Travail.
How to file the DSN
With payroll software
Service Public Entreprendre states that DSN-compatible payroll software is required. The software converts the information on the payslip into DSN data. The features to expect from such a tool are covered in the article Payroll software: the essential features.
For employees under the general social security scheme, the DSN is filed on the net-entreprises.fr website, after prior registration. For employees under the agricultural scheme, it is filed on the MSA website.
Alone or with a third-party filer
The DSN can be filed directly by the employer, handed to a third-party filer such as a chartered accountant, or shared between the two. When registering on net-entreprises.fr, it is possible to open an account to file directly or to appoint another person.
Some management software for small companies includes the director’s payslip, as shown in the comparison of the best accounting software in France. For employees, dedicated payroll software or a third-party filer is still needed.
Without payroll software: the Tese
A business under the general scheme without payroll software can use the Tese (titre emploi service entreprise). According to the official page, this service can be used since 1 January 2026 for all of a company’s employees or only for occasional hiring needs. For the agricultural sector, the equivalent is the Tesa.
After filing: monitoring and anomalies
Once the DSN is sent, the employer checks the dashboard to read the responses from social protection bodies. They send back business reports, called CRM (comptes rendus métier), which group the anomalies detected.
The “Suivi DSN” (DSN monitoring) tool, to be activated in the account profile, sends a report of anomalies. Correcting them quickly avoids discrepancies in employees’ entitlements.
The substitute DSN
If anomalies persist despite several reminders, Urssaf can correct the incorrect data itself: this is the substitute DSN (DSN de substitution). According to the official page, this last-resort mechanism can be used for the first time in June 2026, and initially covers data that affects pension entitlements.
The employer must then inform the employee of the corrections, insofar as they may affect their entitlement to benefits.
Penalties for late filing or errors
The Service Public Entreprendre page checked on 4 May 2026 lists the following penalties:
| Breach | Penalty |
|---|---|
| Failure to file | €20.02 per employee |
| Late filing | €60 per employee per month or part month of delay |
| Delay of 5 days or less | Capped at €6,008 per business per year |
| Omitting an employee | €60 per employee per month or part month |
| Declaring false salaries | €40.05 per employee |
| Declaring false employee information | €13.22 |
Omissions and inaccuracies can be avoided by correcting them within 30 days of filing. Cancellation of late-filing penalties can also be requested if four conditions are met: no breach in the last 24 months, penalties below €4,005, all contributions paid and the DSN filed.
These amounts are those shown on the page on its check date. They may change, and the online page prevails.
Organising the DSN in a small business
- Choose a filing method: payroll software, third-party filer or Tese.
- Open the net-entreprises.fr account and activate DSN monitoring.
- Note the deadlines: the 15th of each month for a business with fewer than 50 employees.
- Report events within 5 working days: sick leave, early return, end of contract.
- Read the reports and correct anomalies without delay.
The DSN concentrates sensitive data: salaries, contact details, absences. Access to the net-entreprises.fr account and the payroll software should be protected by cybersecurity best practices, starting with unique passwords and two-factor authentication.
Frequently asked questions
How does the DSN work for a small business in France?
The DSN (déclaration sociale nominative) is an online filing produced every month from payroll software. According to Service Public Entreprendre (page checked on 4 May 2026), a business with fewer than 50 employees must submit it by the 15th of the month following the paid work period. It is used to pay social contributions and to send each employee’s information to social protection bodies. Sick leave, early returns to work and contract terminations are reported through an event DSN within 5 working days.
What is the DSN deadline for fewer than 50 employees?
The 15th of the month following the paid work period. If that date falls on a public holiday or non-working day, it moves to the next working day. Social contributions are also due on the 15th of the following month, whatever the salary payment date.
Do you need payroll software to file the DSN?
In principle yes: Service Public Entreprendre states that DSN-compatible payroll software is required. Without payroll software, a business under the general scheme can use the Tese service (titre emploi service entreprise), available since 1 January 2026 for all employees or for occasional needs.
What are the penalties for a late DSN?
According to the Service Public Entreprendre page checked on 4 May 2026, a late filing incurs a penalty of €60 per employee per month of delay. If the delay is 5 days or less, the penalty is capped at €6,008 per business per year. Failing to file exposes the employer to a penalty of €20.02 per employee.
What is an event DSN?
It is a DSN sent between two monthly DSNs to report sick leave, an early return to work or the end of an employment contract. It must be submitted within the 5 working days following the event.