O.C.G.A. § 46-2-25 (2019)
Procedure for changing any rate, charge, classification, or service
(a) No person, firm, or corporation (referred to in this Code section as a ‘‘utility’’) subject to the jurisdiction of the commission shall make any change in any rate, charge, classification, or service subject to the jurisdiction of the commission, or in any rule or regulation relating thereto, except after 30 days’ notice to the commission and to the public, unless the
commission otherwise orders, or unless the commission has previously authorized or approved the change. Such notice shall be given by filing with the commission and keeping open for public inspection new schedules stating plainly the changes to be made in the schedules then in force and the time when the changes will go into effect. The commission, for good cause shown, may allow changes to take effect without requiring the 30 days’ notice by an order specifying the changes to be made, the time when they shall take effect, and the manner in which they shall be filed and published. (b) Whenever any new schedule is filed pursuant to subsection (a) of this Code section, the commission shall have authority, either upon written complaint or upon its own initiative without complaint, at once, and, if it so orders, without answer or formal pleading by the utility but upon reasonable notice, to enter upon a hearing concerning the lawfulness of such rate, charge, classification, or service. Pending such hearing and the decision thereon, the commission, upon filing with such schedule and delivering to the utility affected thereby a statement in writing of its reasons for such suspension, may suspend the operation of such schedule and defer the use of such rate, charge, classification, or service, but not for a period longer than five months beyond the time when it would otherwise go into effect, provided that the commission may apply to the Superior Court of Fulton County for an extension of such period, as provided for in Code Section