Member States shall day down quality standards for national mail and shall ensure that they are compatible with those laid down for intra-Community cross-border services.

Member States shall notify their quality standards for national services to the Commission, who will publish them in the same manner as the standards for intra-Community cross-border services referred to in Article 18.

National regulatory authorities shall ensure that independent performance monitoring is carried out in accordance with the fourth subparagraph of Article 16, that the results are justified, and that corrective action is taken where necessary.