Requests for preliminary rulings made by courts of EU Member States have always been dealt with by the European Court of Justice (CJEU). National courts refer requests for preliminary rulings in cases where they require clarity on the interpretation of EU law. As such they play an important role in shaping EU customs law. Over the years the CJEU handled numerous customs cases on tariff classification, customs valuation, origin and procedural customs law.
Source Baker & McKenzie
