The infringement procedure is the only legally binding instrument at the disposal of the European Commission to force Member States to fulfil their obligations. As the guardian of the EC Treaty, and under Article 226 EC, the Commission has the option of commencing infringement proceedings against a Member State, which, in the eyes of the Commission, infringes Community law. The Commission can try to bring the infringement to an end, and, if necessary, may refer the case to the Court of Justice.Is the infringement procedure as it is practised today an adequate instrument for assuring compliance in the internal market? How is it possible to approach and efficiently follow the reasoned opinion of the European Commission? What are the practical steps and the Commission