Preferential tariff treatment claims require prompt correction, notification, and duty payment when importer information is inaccurate. Incorrect claims for preferential tariff treatment must be corrected promptly when the importer believes supporting information is inaccurate and may affect the claim's validity. The importer must amend the import documentation, notify the customs authority of the importing Party, and pay any customs duty and applicable penalties. Voluntary notification before discovery of the error is to be treated as a significant mitigating factor when penalties are considered, provided the importer has rectified the error and paid the duty.