Miss. Code § 77-3-79
The commission may require, by order served on any public utility in the manner provided in this chapter for the service of orders, the filing of such relevant reports, information or data at such time and place as it may reasonably designate.
The commission shall at all reasonable times have access to and the right to inspect and examine all accounts, records, memoranda and property of the public utilities, and it shall be the duty of such public utilities to furnish to the commission, within such reasonable time as the commission may order, any information with respect thereto which the commission may by order require, including copies of maps, contracts, reports of engineers, and other data, records and papers, and to grant to all agents of the commission free access to its property and accounts, records and memoranda when requested so to do. It shall be unlawful for any member, officer, agent or employee of the commission knowingly and willingly to divulge any fact or information which may come to his knowledge during the course of any examination or inspection made under authority of this chapter, except as he may be directed by the commission or by a court or a judge thereof.
The commission shall require an annual reporting from each public utility, the rates of which are subject to regulation under the provisions of this chapter, of all its expenditures for business gifts and entertainment, and institutional, consumption-inducing and other advertising or public relations expenses which the utility claims should be allowed for rate-making purposes. The commission shall not allow as costs or expenses for rate-making purposes any of these expenditures which the commission determines not to be in the public interest. The cost of legislative-advocacy expenses shall not in any case be allowed as costs or expenses for rate-making purposes. Reasonable charitable or civic contributions shall be allowed as cost of service not to exceed amounts established by regulations adopted by the commission.
The commission shall establish filing deadlines for any required periodical reports but in no event shall the filing of such reports exceed sixty (60) days from the due date established by the commission. The commission shall have the authority to extend by order the time of compliance upon a finding that a matter of great urgency exists which would make compliance inequitable. The order extending the time for compliance shall fully set forth the facts justifying such extension. Any public utility which does not furnish such reports, information or other data by the deadlines established by the commission or within the extended time authorized by the commission shall be fined not more than One Thousand Dollars ($1,000.00) per day for each day in violation of the requirements herein that such reports, information or other data are not furnished to the commission.
Miss. Code § 77-3-79