The costs involved in managing the building and public works professional identification card are covered by a fee, the amount of which is set by the union mentioned in article R. 8291-2 and charged to the employers mentioned in the first, second, third and fourth paragraphs of article R. 8291-1 or, where applicable, to the companies using seconded temporary employees. The proceeds of this fee may not be used to finance other tasks entrusted to the union of funds mentioned in Article R. 8291-2.