Anyone may lodge a complaint with the Commission against a Member state about any state measure ( law, regulation or administrative action) or administrative practice which he/she considers incompatible with Community law. However, the Commission’s services may decide whether or not further action should be taken on a complaint in the light of the rules and priorities laid down by the Commission for opening and pursuing procedures.
When the Commission decides to pursue a complaint the Commission allows the Member State to present its views regarding the facts stated in the complaint and the Commission’s initial legal assessment of them, through the letter of formal notice.
The reasoned opinion expresses the Commission’s view that an infringement exists and asks the Member state to remove it within the stated time limit. It is based on the letter of formal notice and is required if no reply to the letter of formal notice is received, or if the observations presented by the Member State in reply to that notice cannot be considered satisfactory. However, nothing prevents the Commission services from negotiating with the Member State throughout the entire infringement procedure.
If no reply to the reasoned opinion is received from the Member State or if the reply is unsatisfactory, the Commission has the possibility to refer the case to the Court of Justice. The Commission is not obliged to do so, but in practice the Commission has always considered that a Member State, which does not follow a reasoned opinion and bring its legislation into conformity with Community law, should be brought in front of the Court of Justice.
Finally, it should be underlined that any finding by the Court of Justice has no impact on the rights of the complainant, since it does not serve to resolve individual cases. It merely obliges the Member state to comply with Community law. It is, therefore, in the complainant’s interest to make use of any redress available at national level, which as a rule enables him/her to assert his/her rights more directly and more personally. When damage has been suffered, only national courts can award reparation from the Member States concerned. This means that individual claims for damages would have to be brought before the national courts, see judgement of 5 March 1996 "Brasserie du pécheur SA" (Cases C-46/93 and C-48/93).
For the detailed information about how to lodge a complaint, please consult the respective information on the Secretariat-General website.