Miss. Code § 77-7-215
No change shall be made in any rate, fare, charge or classification, or any rule, regulation or practice affecting such rate, fare, charge or classification, or the value of the service thereunder, specified in any elective tariff of a common carrier by motor vehicle, except after thirty (30) days' notice of the proposed change, and upon thirty (30) days' notice to all interested carriers, to be given by the carrier proposing such change, filed and posted in accordance with Section 77-7-211. Such notice shall plainly state the change proposed to be made and the time when such change will take effect. The commission may, in its discretion and for good cause shown, allow such change upon notice less than that herein specified, or modify the requirements of this section with respect to posting and filing of tariffs, either in particular instances or by general order applicable to special or peculiar circumstances or conditions.
Miss. Code § 77-7-215