The Commission may, in its discretion, prescribe the forms of any and all accounts, records, and memoranda to be kept by carriers subject to this chapter, including the accounts, records, and memoranda of the movement of traffic, as well as of the receipts and expenditures of moneys.

The Commission shall, by rule, prescribe a uniform system of accounts for use by telephone companies. Such uniform system shall require that each common carrier shall maintain a system of accounting methods, procedures, and techniques (including accounts and supporting records and memoranda) which shall ensure a proper allocation of all costs to and among telecommunications services, facilities, and products (and to and among classes of such services, facilities, and products) which are developed, manufactured, or offered by such common carrier.