The introduction of EU Regulation 883/2004 raised the question of whether the secondment principle must always apply.
An optional approach would mean that if an employer sends an employee on a temporary assignment to another EEA country or Switzerland, provided all secondment conditions are fulfilled, the employer and the employee can agree not to make use of the rules of secondment (i.e. the employee remains subject to the social security legislation of the sending State) but yet to pay social security contributions in the receiving State (based on the general principle that the competent State for social security is the State where the activities are being exercised).
A compulsory application of the secondment principle would mean that opting for the receiving state’s social security scheme would no longer be possible and the home country’s social security legislation would always continue to apply.
In the past, the Belgian social security authorities have always accepted the optional approach to the secondment principle.
Very recently, however, they have decided to change their position. The authorities now consider secondment rules as mandatory for all secondments within Europe for less than 24 months (the home country social security continues to apply). This change of position does not apply to assignments exceeding 2 years, nor to assignments taking place within a bi-lateral treaty.
