Regulations Governing the Customs Clearance of Transit and Transshipment Goods Article 12

Where air transit or transshipment goods are to be transported to a different Customs jurisdiction, the transport operator, freight forwarder, or designated operator shall declare the transit/transshipment applications in entire batches based on the master air waybill (MAWB) or house air waybill (HAWB) as a unit. Separate declarations are not permitted, and the goods shall be transported in an entire batch upon approval by Customs. However, this restriction shall not apply where the goods under the MAWB or HAWB arrive at different airports in batches.
中文原文 轉運及轉口貨物通關管理辦法第12條
空運轉運及轉口貨物運送至其他關區者,運輸業者、承攬業者或指定業者應依主提單或分提單為單位整批申報轉運申請書,不得分開申報,經海關核准後整批運送。
但主提單或分提單貨物分批抵達不同機場者,不在此限。

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