In order to discourage Belgian companies from hiring part-time employees but letting them work on a full-time basis and only paying social security contributions and taxes on their official part-time remuneration, the Belgian legislature introduced a few years ago stringent rules on the publication of part-time work schedules.

Thus, if a company wishes to hire an employee on a part-time basis, specific rules should be taken into account in order to avoid the part-time employee being considered employed on a full-time basis (in which case, social security contributions will be due on the employee's full-time remuneration). Recent case law has clarified some of the main points of this legislation and highlighted several principles.

Requirements for a valid part-time employment contract

A part-time employment contract must be in writing and signed no later than the first day of employment.

The contract must clearly specify the part-time nature of the employment and include the applicable work schedule. A copy of the employment contract of each part-time employee should be made available at the place where the work rules are kept.

Sanctions for non-compliance

If these conditions are not respected, the employee can choose to apply any of the part-time work schedules mentioned in the work rules or, if no schedules are mentioned therein, in any other so-called social document.

Furthermore, if the work schedule for a given part-time employee is not mentioned in his or her employment contract or in the work rules, the National Social Security Office can find that the part-time employee is employed on a full-time basis, in which case social security contributions will be due on the employee's full-time remuneration. It is not sufficient for the employment contract of a part-time employee to simply refer to the applicable work schedule.

Case law

Claims brought by the Social Inspectorate

According to the statutory provisions, if the work schedules for part-time employees are not made public by any of the means described above, the part-time employees will be presumed employed on a full-time basis, unless it was physically impossible for the employees concerned to have worked on a full-time basis. According to the Antwerp Labour Court,[1] this presumption should be interpreted narrowly and must be proven. In other words, if the Social Inspectorate does not investigate the matter and take note of its findings, it cannot rely on this presumption. Consequently, the Social Inspectorate bears the burden of proving that the part-time employees actually worked on a full-time basis.

If the presumption of full-time employment applies, the company can produce proof to the contrary (i.e., proof that the employees concerned could not have been employed on a full-time basis). In this regard, general information on sales which tends to indicate that the employees did not work full time is not sufficient to rebut the presumption. Nor are statements by the employees themselves that they only worked on a part-time basis, in the absence of an objective reason as to why it would not have been possible for them to work full time.[2]

Claims brought by employees

On the other hand, even if the normal work schedules for part-time employees are not published further to the abovementioned rules, a part-time employee cannot claim salary for full-time employment on the basis of the presumption of full-time employment if (s)he is unable to prove that (s)he effectively worked on a full-time basis.[3]