Yes.
It is possible to combine several activities as an employee (provided that this is not prohibited by a clause of the employment contract), on condition that the limit of 40 hours worked per week is not exceeded. If, as a result of combined working, the normal working time were to exceed 40 hours per week, the employee would have to comply with a number of rules.
The Labour Code makes it clear in fact that an employee combining his waged work with one or more other waged posts is required to notify the Inspectorate of Labour and Mines (ITM) of the posts held, where the normal working time involved exceeds 40 hours per week as a result of that combination.
It is important to note that the ITM may arrange to receive from the Joint Social Security Centre (Centre Commun de la Sécurité Sociale) or from by their various social security institutions the information needed to oversee the application of the above-mentioned provisions.
An employee who does not fulfil the above-mentioned obligation of notification is liable to a fine of € 251 to € 5,000. Similarly, the refusal to provide information requested or refusal to provide it within the prescribed period or the fact of providing incorrect information attract a fine of € 251 to € 2,500.