Regulations Governing Number Portability Article 18

Mobile Network Operator shall maintain reasonable quality of customer services and quality of network performance, when providing communications services for Ported Subscribers. By January 10 and July 10 of each year, each Mobile Operator shall compile and submit information on the number of Subscribers ported to/from its networks, the failure rate of porting process, average duration of porting process, additional call set-up delay time on average calculated by calling sampled Ported Subscribers, and so on, for the previous six months to the NCC. The report formats shall be formulated and announced by the NCC.
中文原文 號碼可攜服務管理辦法第18條
行動經營者向攜碼用戶提供通信服務時,應維持合理之客戶服務品質及網路性能服務品質。
行動經營者應於每年一月十日及七月十日前彙整其前六個月攜碼用戶移入與移出數量、移轉作業失敗率、平均移轉作業時間,及抽樣攜碼用戶之受信平均額外呼叫建立時間等資料,提報予本會;其提報格式,由本會訂定公告之。

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