Customs Act Article 62

I. In the case where imported goods are returned or exported by transshipment due to a mistake made during loading, excessive unloading or any other special reasons prior to declaration, an application shall be submitted to Customs for approval within fifteen days following the importation date of the transportation carrying such goods; such goods shall be returned in their original form or exported by transshipment within ninety days. In the case in which an application cannot be submitted on time, an application for storage in a bonded factory shall, prior to expiration of the stipulated period, be submitted to Customs in accordance with Article 58.II. If the preceding paragraph is not complied with, the goods shall be sold or disposed of, in accordance with Paragraph 2, Article 73 mutatis mutandis.
中文原文 關稅法第62條
進口貨物在報關前,如因誤裝、溢卸或其他特殊原因須退運或轉運出口者,應於裝載該貨之運輸工具進口之翌日起十五日內向海關申請核准,九十日內原貨退運或轉運出口;其因故不及辦理者,應於期限屆滿前,依第五十八條規定向海關申請存儲於保稅倉庫。
不依前項規定辦理者,準用第七十三條第二項規定,將其貨物變賣、處理。

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