Declaration of incapacity of an employee
Dealing with incapacity for work can be a difficult and stressful time for an employee. That's why this online section exists to facilitate the declaration process and provide valuable support throughout the employee's journey.
In a nutshell
As an employee, during a period of sick leave, there are rights and obligations towards the employer and the CNS.
The following information is available on this page:
- The procedure and deadlines to be respected to declare an incapacity for work or its extension, whether for a resident of Luxembourg or a cross-border worker;
- The sanctions incurred in the event of failure to declare or falsification of a certificate of incapacity for work.
Everything you need to know
- The declaration
- Deadlines
- The procedures
- Sanctions
Declaration of incapacity for work for residents of Luxembourg
To declare incapacity for work, it is compulsory to use the form issued by the doctor, which consists of three parts. This form contains the following information:
- The 13-digit identification number;
- The start and end dates of the incapacity for work;
- The diagnosis code;
- The date the report was drawn up
- The stamp or signature of the prescribing doctor.
Good to know: the 13-digit identification number is composed as follows: YYYYMMDD for the year, month and day of birth, and XXXXX which represent the five personal digits.
The stages of the declaration are as follows:
- Sending the first part: The original must be sent to the CNS by post. It is important to keep a copy and to mention the 13-digit identification number in the subject line.
- Transmission of the second part: This part must be sent to the employer.
- Keeping the third part: This part must be kept for personal records.
For more information, you can consult the section entitled: Obligations towards the employer in the event of incapacity for work.
Declaration of incapacity for cross-border workers
The 13-digit identification number issued in Luxembourg must appear on the certificate of incapacity for work. If the doctor has not entered it, you can add it yourself, provided you do not use the sections reserved for the doctor. Any changes to these sections may result in sanctions and the invalidity of the certificate (see below the section, ‘Sanctions for failure to declare or falsification’).
The certificate issued by the doctor may not be identical to the one used in Luxembourg. The procedures vary depending on the country of residence:
- Residents of France: The doctor issues a certificate consisting of a part 1 for health insurance and a part 2 for the employer.
- Residents in Germany: If the electronic certificate (eAU) is in force, it is necessary to request a printed copy to send to the CNS by post.
- Residents in Belgium: If the certificate has only one section, a duplicate must be requested from the doctor to be sent to the employer.
Deadlines for declaring incapacity for work
When an employee is unable to work, certain rules must be followed to declare this incapacity to the CNS and ensure proper administrative processing.
Absence of 2 working days or less
If the incapacity for work does not exceed two working days, no declaration to the CNS is required, either by mail or by telephone.
Absence from work of 3 days or more
For incapacity for work of three days or more, the medical certificate must be sent to the CNS before the end of the third working day of absence. As evidenced by the postmark, this applies whether the employee is in their usual country of residence or abroad at the time of illness.
Retroactive effect of the certificate of incapacity for work
The medical certificate must be issued no later than the third day of incapacity for work or its extension. It can therefore have a retroactive effect of a maximum of two days. Beyond that, it will only be taken into consideration by the CNS from the date of its issue.
For example, if an employee falls ill on a Monday and consults a doctor on Wednesday, the sick leave can be established from Monday. However, if the consultation only takes place on Thursday, the CNS will consider the incapacity for work from that date.
Extension of incapacity for work
In the event of an extension of the incapacity, the new certificate must be sent to the CNS before the end of the second working day following the expected date of return to work.
Some concrete examples to clarify things: Calculating the deadline for the declaration
Incapacity starting on a Monday
If the incapacity for work starts on a Monday, the medical certificate must be sent to the CNS by Wednesday at the latest (3rd working day).
- Part-time employment
For a part-time employee who does not work on Monday and falls ill on that day:
→ The employer must be informed on the Tuesday, the first day of absence. The medical certificate must be sent to the CNS by Thursday at the latest.
- Non-working days
If the incapacity for work begins on a Friday, with Saturday and Sunday as non-working days:
→ The medical certificate must be sent to the CNS by the following Tuesday at the latest.
- Extension
If the initial certificate indicates a return to work on a Wednesday, but the incapacity is extended:
→ The new certificate must be sent by Friday at the latest (2nd working day following the planned day of return to work).
- Extension and non-working day
If the last day for sending the extension certificate falls on a non-working day (Saturday, Sunday or public holiday):
→ The deadline is extended to the next working day. For example, if work is scheduled to resume on a Friday and the second working day after that is a Sunday, the certificate must be sent by the following Monday at the latest.
Declaration of the employee's incapacity for work
Online
Use the form ‘Déclaration d'une incapacité de travail à la CNS’ (Declaration of incapacity for work to the CNS).
By post
The employee sends their certificate of incapacity for work by post to the following address (without postage from Luxembourg):
Caisse nationale de santé
Indemnités pécuniaires
L-2980 Luxembourg
Declaration of incapacity for work by the employer
The National Health Fund (CNS) determines the total number of cases of incapacity for work on the basis of the employer's monthly declarations and the medical certificates sent by the employee. It is crucial that these declarations, from the employee AND the employer, are made correctly and without delay, as they determine who, between the employer or the CNS, is responsible for paying the salary for a given month. If the declarations are not made correctly, this can lead to errors in the calculation of benefits and in the coverage of payments by the CNS.
Sanctions for failure to declare and falsification of a certificate of incapacity for work
Failure to declare a certificate of incapacity for work
If a certificate of incapacity for work is not sent to the CNS, the latter will send a reminder by post, inviting the insured person to fulfil their obligation. But beware! In the event of a repeat occurrence, the CNS may, pursuant to Article 447 of the Social Security Code, impose an administrative fine of up to €750.
Falsification of a certificate of incapacity for work
Please note! Any suspicious certificate is reported by the CNS department responsible for processing medical certificates to the department dedicated to the fight against abuse and fraud for investigation.
Good to know: any modification of the data in the sections reserved for the doctor, by the insured person or by a third party, exposes the latter to a fine, to the invalidity of the certificate and to a denunciation of the facts to the State Prosecutor.
The certificate is declared invalid in all cases. However, the amount of the fine depends on the seriousness of the offence:
- Modification of data relating to a period of up to three days‘ incapacity for work: 200 euros;
- Modification of data relating to a period of more than three days’ incapacity for work: 500 euros;
- Repeat offence, regardless of the duration concerned: 750 euros.
How do I send a sick note to the CNS?
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