In a judgment delivered on Wednesday 11 July in Case C-356/15, the European Court of Justice held that Belgian law infringes European Union law governing the posting of workers.
A1 certificates (formerly E101) are documents issued to workers to indicate that in the event of posting they continue to be subject to the social security scheme of their country of origin.
Belgian law stipulates that when it is considered that an A1 certificate has been incorrectly issued in another member state, the competent national authorities may, unilaterally and without following the procedure for dialogue and conciliation provided for by Regulations 883/2004 and 987/2009, require the workers concerned to be covered by Belgian social security.
In its decision, the Court upholds the European Commission's action for failure to fulfil obligations.
The European Court points out that: - A1 certificates are binding on the institutions of other member states as long as they are not withdrawn or declared invalid by the State in which they were established; - procedures exist to challenge the validity of an A1 certificate.
According to the Court, the principle of loyal cooperation and the objectives pursued by EU legislation on posted workers would be infringed if the member state of posting adopted legislation allowing its own institutions to consider unilaterally that they are not bound by the A1 certificate and to subject these workers to its own social security scheme.
Furthermore, in the event of doubts about the validity of A1 certificates, the issuing authorities must, in accordance with the principle of loyal cooperation, reconsider the validity of the issue of certificates and, where appropriate, withdraw them.
If these authorities fail to carry out such a review within a reasonable period of time, proceedings may be brought before the courts of the member state of posting to exclude the certificates in question (see EUROPE 11955).
Moreover, the Belgian regulations fail to meet these conditions. On the one hand, it does not provide any obligation to initiate the dialogue and conciliation procedure with the issuing institution and on the other, it does not reserve the national court with the power to ascertain the existence of fraud and to exclude A1 certificates for this reason. (Original version in French by Mathieu Bion)