Regulations Governing the Work Permit for Attorneys to Employ Foreigners as Assistants or Consultants Article 11

During the validity period of an employment permit, if it becomes necessary for a foreign employee to have a new employer, the new employer shall re-apply to the Ministry of Justice for an employment permit.
中文原文 律師聘僱外國人從事助理或顧問工作許可及管理辦法第11條
律師所聘僱之外國人於聘僱許可有效期間內,如需轉換雇主者,應由新聘僱之律師向法務部重新申請聘僱許可。

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