Article 7:404 Dutch Civil Code, Book 7

If the assignment has been given with a view to a person who carries on a profession or business together with the service provider or in its employment, that person is obliged to perform the work necessary for performing the assignment himself or herself, save in so far as it follows from the assignment that he or she may have it carried out by others under his or her responsibility; all without prejudice to the liability of the service provider.