Classification of solar panels depends on whether fitted elements supply power to external loads; impacts tariff heading assignment. Where fitted elements in a solar panel/module supply power to an external load (for example a motor or an electrolyser), classify the module under CTH 8501; where such elements do not supply power to an external load, classify the module under CTH 8541. Importers and customs brokers must apply this functional test for tariff classification and report any difficulties to the customs office.