Regulations Governing Customs Clearance Procedures for Air Express Consignments Article 20

Payment of duties and charges on import express consignments shall be accomplished in accordance with the provisions prescribed in the Regulations Governing the Implementation of Post-Release Duty Payment Procedures for Imported Goods, or through a security deposited in advance, and then deducted online when the consignments are clearing Customs.
中文原文 空運快遞貨物通關辦法第20條
快遞貨物應繳之各項稅費得依進口貨物先放後稅實施辦法規定辦理或預繳稅費保證金採線上扣繳方式辦理。

English translation for reference only; the Chinese text prevails. Not legal advice.