Copyright Collective Management Organization Act Article 11

A member of a CMO shall be an economic rights holder.An economic rights holder may not be at the same time a member of two or more CMOs providing the same collective management services.If an economic rights holder violates the provision of the preceding paragraph and joins two or more CMOs at different times, the rights holder will be deemed to have not joined the CMO or CMOs it entered at later times; a rights holder who joins two or more CMOs at the same time shall choose membership in only one among them within 30 days after the time it joins; a rights holder that fails to make a choice within 30 days will be deemed to have joined none of the CMOs.
中文原文 著作權集體管理團體條例第11條
集管團體之會員應為著作財產權人。
著作財產權人不得同時為二個以上辦理相同集管業務之集管團體之會員。
違反前項規定,其先後加入者,就後加入之集管團體,視為未入會;其同時加入者,應於加入時起三十日內擇一集管團體加入,未於三十日內選擇者,視為均未入會。

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