Referendum Act Article 31
If a referendum proposal is rejected, the competent authority shall announce the results of the referendum within seven days of the completion of voting and notify the lead proposer.
中文原文 公民投票法第31條
公民投票案不通過者，主管機關應於投票完畢七日內公告公民投票結果，並通知提案人之領銜人。