Administrative Regulations for Number Portability Services of Telecommunications Enterprises Article 27

When Ported Subscribers terminate use of their original numbers, Recipient Operator shall, within 7 days from the termination of the subscribers, return the subscribers’ numbers to the original operator allocatedwith the number and report to the Centralized Databases Administrator. However, of the original operator assigned that subscriber’s number has stopped its business operation or that subscriber’s number is no longer allocated to any operator, that subscriber’s number shall be returned to the competent authority.Situation of terminate use as referred to in the preceding paragraph does not include the conditions that an inheritor continues to use a telephone number through inheritance, or a surviving or new company continues to use its forerunner's telephone number after consolidation or merger, or number Ported Subscribers under service agreement to the Recipient Operator apply for the third party continue to use the original telephone number.Unless a Ported Subscriber ceases to use his/her existing subscriber’s number, the Donor Operator shall not reassign that subscriber’s number to another Subscriber.