Regulations Governing The Implementation Of Automated Cargo Clearance Procedures Article 17

A through-Customs value-added network and CPT Single Window shall keep all electronic Customs declaration and relevant files recorded by its computer for at least five years following the date on which the cargoes concerned are released, and may destroy them afterward.A through-Customs value-added network shall keep all manifest and shipping bills for export files recorded by its computer for at least five years following the date on which the cargoes concerned are released and, except otherwise agreed by the stakeholders, may destroy them afterward.
中文原文 貨物通關自動化實施辦法第17條
通關網路或單一窗口記錄於電腦之報單及其相關檔案應自進出口貨物放行之翌日起保存五年,期滿予以銷毀。
通關網路記錄於電腦之艙單、出口裝船清表檔案,應自進出口貨物放行之翌日起保存五年,期滿除另有約定外予以銷毀。

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