Interoperability is a political priority as it comes to electronic tolling in Europe. The idea of numerous on board units behind the windscreen of European trucks is a true politicians nightmare. Still the number of on-board equipment (OBE) is increasing while the answer to stopping this, the European Electronic Tolling Service (EETS), is not taking off. In this paper the specific complexity of EETS and the interoperability Directive are looked at from the perspective of a public toll charger. This perspective is relevant because in many Member States motorways are publicly owned and operated, and road user charges consequently will be public money, often levied as a tax. These circumstances do not seem to match very well with the starting points of the Directive that more or less seems to presuppose private roads were private service providers can collect private service fees for the private toll chargers. In this paper the political and legal problems will be represented and put out for discussion