(1) Subject to paragraphs (2), (3), (4) and (5) and the provisions of the Act of 2011, an undertaking shall ensure that traffic data relating to subscribers and users processed and stored for the purpose of the transmission of a communication shall be erased or made anonymous when it is no longer needed for that purpose.

(2)

(a) An undertaking may process traffic data necessary for the purpose of subscriber billing and interconnection payments only up to the end of the period in which the bill may be lawfully challenged and payment pursued or where such proceedings are brought during that period until those proceedings are finally determined. An undertaking shall inform its subscribers of the types of traffic data that are processed and of the duration of such processing.

(b) Legal proceedings shall be deemed, for the purpose of this paragraph, to be finally determined -

(i) if no appeal is brought within the ordinary time for an appeal by either party to the proceedings, upon the expiry of that time,