Regulations Governing Number Portability Article 15

When a Ported Subscriber ceases to use his/her existing telephone number, the Recipient Operator shall return that telephone number to the original Mobile Operator assigned it within seven days either thereof or after an announcement service, if any, is terminated, and shall perform the required notifications in accordance with the provisions set forth in Item 10, Paragraph 1 or Paragraph 5 of Article 22. As the original service provider assigned that telephone number has stopped its business operation or that telephone number is not held by any Operator, that telephone number shall be returned to the NCC.The term “cease to 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 contract to the Recipient Operator apply for the other user continue to use the original telephone number.Unless a Ported Subscriber ceases to use his/her existing telephone number, the Donor Operator shall not reassign that telephone number to another Subscriber.