Social Worker Act Article 16

When performing their duties, social workers shall prepare social work records, which must be maintained by the agency, institution, organization, or office where they practice. Such records shall be retained for no less than seven years.
中文原文 社會工作師法第16條
社會工作師執行業務時,應撰製社會工作紀錄,其紀錄應由執業之機關(構)、團體、事務所保存。
前項紀錄保存年限不得少於七年。

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