How to set up Nominal Social Declaration (DSN)? | MIA Assurances

Nominal Social Declaration, or DSN, generalized since January 1st, 2019, is a mandatory formality for all companies employing people in France. Previously, companies had to send a declaration (DADS-U) each year to the various social organizations (Pôle emploi, Social Security, Urssaf, etc).

From now on, it is done once a month in the format of a single declaration, sent directly to all providers and organisations. This declaration includes all the information regarding your employees, necessary for the processing of their social rights and benefits.


Two types of information are transmitted via DSN:

– The declarations of social security contributions resulting from remunerations: this data is entered once a month after generating the payslips.

– The recording of exceptional events: work accident, sick leave, maternity leave, end of contract, etc.

The DSN flow must include the following information to avoid rejection:

– The amount of salary paid and the contributions indicated on the pay slips

– The SIRET number of your company

– The references of the medical, death and disability, and supplemental pension contracts

We would like to draw your attention specifically around benefits: it is common for insurance companies to have difficulties in finding your declarations due to input errors on your contract references. A double check is useful to avoid unnecessary additional steps and delays in processing.

– Social Security number of your employees


If your company employs less than 50 members of staff, it is advisable to make your registration before the 15th of the month following the payment of the salary. If you have more than 50 employees, you must make your declaration before the 5th of the month.If the declaration is to be made after an event, you have 5 days to do so.


If your company belongs to the general Social Security regime

  1. Create your account on Net Entreprises.
  2. Carry out your monthy declaration:

– Either online on the Net Entreprises website, via a file deposit

– Or directly from your payroll management tool, using the Neodes standard, if it has been properly configured beforehand. Each year, it is necessary to record in your payroll software the information coming from the Configuration forms of the Complementary Organizations (FPOC).

If your company belongs to the agricultural Social Security regime
Operations are to be carried on the Mutualité sociale agricole (MSA) website.


Once data has been sent via the DSN, it is checked and then sent to the providers. You will then receive either a certificate of conformity if the DSN is validated, or an error report if the DSN is rejected.

The DSN setup has multiple goals:
– Save time for HR and social / benefits providers
– Avoid manual mistakes
– Fight fraud
– Facilitate access to social services

The use of DSN is mandatory, and subject to penalties of up to €750 per month. However, some companies cannot use DSN, or choose not to use DSN. In this case, it is advisable to register to the service of “titre emploi service entreprise” (Tese) which will make the declaration. This free service allows companies to make their declarations online (see downloadable guide).

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