Enforcement Rules of the Labor Insurance Act Article 9
Employed persons with no definite employer or self-employed and participating in two or more professional labor unions shall select the major union as their basis for insurance coverage.
中文原文 勞工保險條例施行細則第9條
無一定雇主或自營作業而參加二個以上職業工會為會員之勞工，由其選擇主要工作之職業工會加保。