Each public utility, except a utility operated by an affected county, must keep uniform accounts as prescribed by the commission of all business transacted. The classification of utilities, index of accounts, definitions, and general instructions pertaining to each uniform system of accounts, as amended from time to time, must be adhered to at all times, unless provided otherwise by these sections or by rules of a federal regulatory body having jurisdiction over the utility, or unless specifically permitted by the commission.
  (1) System of accounts. For the purpose of accounting and reporting to the commission, each public utility must maintain its books and records in accordance with the commission's approved system of accounts, or if the commission has not approved a system of accounts, the following prescribed uniform system of accounts:
    (A) Class A Utility, as defined by §24.3(5) of this title (relating to Definitions of Terms); the uniform system of accounts as adopted and amended by the National Association of Regulatory Utility Commissioners (NARUC) for a utility classified as a NARUC Class A utility.
    (B) Class B Utility, as defined by §24.3(6) of this title; the uniform system of accounts as adopted and amended by NARUC for a utility classified as a NARUC Class B utility.
    (C) Class C Utility, as defined by §24.3(7) of this title; the uniform system of accounts as adopted and amended by for a utility classified as a NARUC Class C utility.
    (D) Class D Utility, as defined by §24.3(8) of this title; the uniform system of accounts as adopted and amended by a utility classified as a NARUC Class C utility.
  (2) Accounting period. Each utility must keep its books on a monthly basis so that for each month all transactions applicable thereto are entered in the books of the utility.

Source Note: The provisions of this §24.127 adopted to be effective October 17, 2018, 43 TexReg 6826; amended to be effective May 7, 2020, 45 TexReg 2845