Where the customs authorities have good reason to suspect that a certificate made available to them in accordance with Article 2(1) has been falsified, they may request an expert opinion from a representative of the national aviation authorities. The importer shall bear the costs of the expert opinion.

When deciding whether to request an expert opinion, the customs authorities shall take into account the risk that the cost of the expert opinion would outweigh the benefit to the importer of the suspension of duties, in the event that according to the expert opinion the rules for the issuing of those certificates have not been infringed.