Miss. Code § 27-19-95
All certificates of public convenience and necessity and permits granted by the Mississippi Public Service Commission authorizing the operation of common and contract carriers of property or passengers shall be exempt from taxation. No vehicle shall be registered as a common or contract carrier of passengers or property, nor a license issued for such vehicle, unless the owner or operator thereof shall have qualified with the Mississippi Public Service Commission and obtained a certificate of public convenience and necessity or permit, and shall have paid all fees to the Mississippi Public Service Commission, required by law, if the carrier be one required to qualify with the Mississippi Public Service Commission. When any vehicle is qualified with the Mississippi Public Service Commission as a common or contract carrier of property or passengers, and the owner or operator thereof has procured a certificate of public convenience and necessity, or a permit, from the Mississippi Public Service Commission, such vehicle shall not be registered and licensed in any classification other than the classification of a common or contract carrier, either of property or of passengers. The Mississippi Public Service Commission shall promptly transmit, or cause to be transmitted, to the State Tax Commission, a copy of all certificates of public necessity and convenience, and permits hereafter issued to common and contract carriers of property or passengers, together with a list giving full and complete description of all vehicles qualified by such carrier with the public service commission.
If any person shall operate a motor vehicle which is required by law to qualify with and obtain a certificate or permit from the Mississippi Public Service Commission without having so qualified with and obtained a certificate or permit from the Mississippi Public Service Commission, and without having obtained the proper license tag from the State Tax Commission, such person shall, notwithstanding the provisions of this section, be liable for the full privilege license tax and the penalty thereon as is otherwise provided by this article and the State Tax Commission shall collect such tax and penalty from such person. The State Tax Commission shall not, however, issue a license tag for such vehicle unless the owner or operator thereof shall thereafter qualify with the Mississippi Public Service Commission, at which time the proper license tag shall be issued.
Miss. Code § 27-19-95