Mississippi Code
Article 1 - General Provisions
§ 27-59-31. Penalty for operating without compressed gas user's decal

No person shall operate or cause to be operated, upon the highways of this state, a motor vehicle or motor vehicles that use or are capable of using compressed gas as a motor fuel, when such person has not paid the taxes levied in this chapter and the motor vehicle does not display a compressed gas user's decal.
Any person who does not file an application to obtain a compressed gas user's decal within fifteen (15) days from the date of the installation of the compressed gas carburetion equipment or the acquisition of a motor vehicle or motor vehicles with such equipment attached or who fails to file a renewal application within fifteen (15) days after the expiration of the compressed gas user's decal shall be liable for the full amount of the annual privilege tax or prepaid portion thereof and a penalty of twenty-five percent (25%) of the taxes levied herein may be added as damages.
If any county tax collector shall enforce the collection of any delinquent annual privilege tax or annual permit fee, together with the penalty thereon required by law, then such county tax collector shall be entitled to one-half (1/2) of the penalty. The fee shall be forfeited by the county tax collector if he shall fail to forward any application and remittance within fifteen (15) days of receipt by him.