Louisiana Revised Statutes Tit. 47, § 828. Interest

When any person subject to the provisions of this Chapter fails to pay or remit the tax, or any portion thereof, on or before the day when it is required to be paid or remitted to the secretary of the Department of Revenue under the provisions of this Chapter, interest at the rate of one and one-half percent per month shall be added to the amount of tax due and such interest shall be computed from the due date until the tax is paid. The interest provided for herein shall be an obligation to be collected and accounted for in the same manner as if it were a part of the tax due and can be enforced in a separate action or in the same action for collection of the tax and shall not be waived.