(9)Substantiated complaints submitted by natural or legal persons can constitute an important source of information for both market-surveillance authorities and approval authorities. In that context, the establishment of straightforward and proportionate processes that allow natural and legal persons to submit substantiated complaints to the respective authorities where they have reason to believe that this Regulation is not complied with can contribute to the application and enforcement of this Regulation. Those complaints should be considered by national authorities as a risk factor in decisions on market surveillance or in-service conformity activities.