Electronic and Postal Communications (Tariffs) G.N. No. 421 (contd) prevent market entry or distort competition by applying tariffs below the underlying cost of service provided. Filing and publication of tariff 5.-(1) A licensees shall on a quarterly basis file the schedule of their tariffs with the Authority (2) A licensee shall not charge his customers tariffs that have not been filed with the Authority. (3) A licensee shall on quarterly basis publish its tariffs in the printed and electronic media in English and Kiswahili. (4) The dominant licensee shall inform the Authority in advance of any intended changes in tariff by submitting notifications to the proposed changes seven days before the proposed tariff comes into effect. (5) A dominant licensee shall upon approval by the Authority ensure that the tariffs or charges are published in the public media immediately before coming into effect. Approval of tariffs for regulated services 6.-(1) The tariffs for regulated services filed by the dominant licensee shall be approved by the Authority. (2) The Authority may from time to time publish or print tariffs for regulated services in electronic media in English and Kiswahili. (3) A dominant licensee shall charge regulated services using tariffs that have been filed with and approved by the Authority. (4) All applications for approval of tariffs for regulated services shall be filed with the Authority and shall(a) conform to the form, manner and methodology specified in the Rules issued by the Authority; and (b) be accompanied by relevant documents, including all calculations notes and any other information in support of the application. 86