DSN Explained: France's Monthly Payroll Filing for Foreign Employers

If you employ people in France, one acronym will follow you every month: DSN. It's the backbone of French payroll compliance — and the thing foreign employers most often underestimate. Here's what it is, what it covers, and why getting it right (and on time) matters.

What is the DSN?

DSN stands for Déclaration Sociale Nominative — the "nominative social declaration". It's a single, electronic, monthly declaration, generated from your payroll, that replaces what used to be a stack of separate filings. In one file, it reports each employee's pay and contributions to all the relevant bodies at once: social security, pension funds (Agirc-Arrco), unemployment insurance, and the tax authorities (including income tax withheld at source).

What does the DSN declare?

• Each employee's gross pay and net pay;
• All employer and employee social contributions;
• Income tax withheld at source (prélèvement à la source);
• Life-events for each employee, through what are called "event" declarations.

Monthly filing and "event" declarations

There are two rhythms to keep in mind:

• The monthly DSN, filed after each payroll run;
• Event declarations (DSN évènementielle) filed as things happen — a new hire, a sick leave, the end of a contract. These have their own short deadlines.

What are the deadlines?

The monthly DSN is due on the 5th of the following month for companies with 50 or more employees (where salaries are paid in the same month), and on the 15th of the following month for smaller companies. Event declarations follow their own timeframes. Miss a deadline, or file incorrect data, and penalties apply — and errors can cascade into employees' pensions and benefits, which creates friction with your team.

What this means for a foreign employer

You have two situations:

• If you register through the simplified foreign-employer scheme (TFE), part of the process is streamlined for you.
• If you run standard payroll (via a French entity or a full foreign-employer registration), you produce a full monthly DSN like any French employer.

In both cases, the DSN has to be accurate and on time, every single month. It's technical, it's in French, and it's unforgiving of mistakes — which is exactly why most foreign companies hand it to a specialist.

How I handle it for you

I produce your payslips and file your DSN — monthly and event declarations — correctly and on time, using Silae (the leading French payroll software). You get compliant payroll without touching the French system yourself, and a single contact who explains everything in English.