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# How do I declare incapacity for work with a French medical certificate?

If you are a cross-border worker residing in France and receive a medical certificate for sick leave from a French doctor, you must follow a specific procedure to declare your incapacity for work to the CNS (Caisse Nationale de Santé).

## Important change: New secure Cerfa forms required

Since July 1st, 2025, France requires the use of secure Cerfa forms for all work incapacity certificates. These forms include security features such as holograms and magnetic ink.

||| As of September 1st, 2025, old non-secure Cerfa forms are officially rejected by French Health Insurance and by the CNS. Only the new secure Cerfa forms are accepted.

## Recording sick leave

First, record the employee's sick leave in Salary.lu following the standard process:

1. Log in to your Salary.lu account
2. Go to the "Leaves" section
3. Select the employee concerned
4. Add the sick leave dates according to the medical certificate
5. Save the leave record

|| Make sure the leave period matches exactly the dates mentioned on the medical certificate.

## Submitting the certificate to the CNS

After recording the sick leave in Salary.lu, you must separately submit the French medical certificate directly to the CNS:

1. Ensure you have the new secure Cerfa form from the French doctor
2. Scan or photograph the certificate clearly
3. Prepare the file in PDF format (maximum 5 MB, well-readable and properly framed)
4. Go to the CNS online form: [Declaration of incapacity for work](https://cns.public.lu/fr/assure/remboursements/demarches-frequentes/formulaire-declaration-incapacite-travail.html)
5. Fill in all required fields
6. Upload your PDF certificate
7. Click "Preview" to review your information
8. Click "Send" to submit to the CNS
9. You will receive a confirmation email

||| This submission to the CNS is separate from your Salary.lu sick leave recording. Salary.lu does not automatically submit French medical certificates to the CNS.

| For more information about the new secure forms, visit the [CNS announcement page](https://cns.public.lu/fr/assure/actualites/certificat-incapacite-france-nouveau.html).