Retention of electronic communications data: CJEU Advocate General issues opinion on the criteria for assessing the compatibility of national legislation with EU law

09 September 2026

On 3 September 2026, the European Court of Justice (CJEU) issued an important opinion of the Advocate General at the Court, Maciej Szpunar.

In 2022, Belgium adopted new legislation relating to the collection and retention of identification data and metadata in the electronic communications sector. That legislation is intended, inter alia, to regulate the retention of certain traffic and location data by providers of electronic communications services in order to combat fraud, malicious use of the network and breaches of network security.

Directive 2002/58 on privacy and electronic communications establishes a strict framework governing the retention of those data. It aims to reconcile the objectives of general interest pursued by the Member States with respect for fundamental rights, in particular the right to respect for privacy and the protection of personal data guaranteed by the Charter of Fundamental Rights of the European Union.

The Belgian Constitutional Court, before which five actions have been brought, has referred questions to the Court of Justice concerning the compatibility of certain provisions of the 2022 legislation with EU law.

In his Opinion, Advocate General Maciej Szpunar proposes that the Court should find that EU law precludes several of the rules contained in the Belgian legislation at issue.

He recalls, first of all, that the national measures requiring the retention of traffic and location data constitute an interference with the fundamental rights to respect for privacy and the protection of personal data. Such interference is permissible only if provided for by law, is strictly necessary and complies with the principle of proportionality. He also states that the assessment of the compatibility of a national regime for the retention of data depends on the seriousness of the interference which it entails and the importance of the objective pursued.

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