The Regulations Governing the Implementation of Advance Tariff Classification Ruling on Imported Goods Article 9

Customs may modify the result of advance ruling and shall notify the concerned Applicants of the modifications with clear explanation in writing. If the Applicant is able to prove that a contract has been entered into, the transaction has been conducted according to the contract, and the change in tariff classification will cause loss, the Applicant may apply for an extension of the application of the modified ruling, but such an extension shall not exceed 90 days.In the case where modifying an advance tariff classification ruling involves changes in import regulations, the imported goods shall be subject to the applicable import regulations in effect at the time of importation.