call. If the level of the charge changes during the phone call, the provider of a premium rate service shall inform the end user about this change 10 seconds before the rate change. 8. A premium rate service shall be provided under an agreement concluded as described in the second sentence of Article 56 (2). Article 64a. The provider of publicly available telecommunications services shall be obliged, at the subscriber's request to: 1) block, free of charge, outgoing calls to premium rate numbers and incoming calls from such numbers, 2) block, free of charge, outgoing calls to numbers of particular types of premium rate services and incoming calls from such numbers, 3) provide the possibility for the subscriber to define a maximum price for a service measurement unit or for a call, if the service is charged per call, and to block, free of charge, outgoing calls to premium rate numbers the price of which exceeds a maximum price defined by the subscriber in its request, and incoming calls from such numbers – unless such calls do not create payment obligations on the subscriber's part. Article 65. 1. A provider of additional benefits referred to in Article 64 (1) shall submit to the President of UKE at least 7 days before it starts to provide this service, information with regard to: 1) its name (company name), address and seat; 2) name, type and the scope of the premium rate service provided; 3) the number or numbers used to provide premium rate services; 4) the start-up date for the provision of premium rate services. 2. The President of UKE shall keep a public register of numbers used to provide premium rates services containing information referred to in paragraph 1. The register shall also list the date of submitting information to the President of UKE. 3. The President of UKE shall publish the register referred to in paragraph 2 on the UKE BIP website. Article 66. 1. A provider of publicly available telephone services in a fixed-line network shall make available to its subscribers, at a cost-oriented price, an up-to-date directory of subscribers with assigned numbers within a numbering area in which the subscriber’s network termination point is based, at least once every 2 years. 2. A provider of publicly available telephone services shall provide its subscribers with a telephone directory enquiry service, including at least its subscribers who have made available the data referred to in Article 60a (1a). Article 67. 1. A provider of publicly available telephone services shall make available the necessary data to other telecommunications undertakings which keep directories or provide a telephone directory enquiry service, including a nationwide directory as well as a comprehensive directory enquiry service comprising all subscribers of publicly available telephone services in the territory of the Republic of Poland, hereinafter called the “nationwide telephone directory enquiry service”. 2. The data shall be made available under an agreement which is governed by the provisions of Articles 27-31 respectively. The agreement shall in particular specify the form of making the data available. 3. The provisions of Articles 161 and 169 shall respectively apply to a telephone directory enquiry service and to the preparation of a directory as well as to the related process of making the data available.