Enforcement Rules of the Labor Insurance Act Article 29
The insurer shall separately calculate payable insurance premiums in accordance with the insured persons' insurance salaries reported by the insured units each month and prepare insurance premium payment bills with the statements of methods of calculation regularly. The bills shall be sent to the insured units by mail or via electronic transmission before the 25th day of the next month and request them to pay the premiums.
中文原文 勞工保險條例施行細則第29條
保險人每月按投保單位申報之被保險人投保薪資金額，分別計算應繳之保險費，按期繕具載有計算說明之保險費繳款單，於次月二十五日前寄發或以電子資料傳輸方式遞送投保單位繳納。