Louisiana Revised Statutes Tit. 47, § 337.69. Interest on unpaid taxes

A. When any taxpayer fails to pay a tax, or any portion thereof, on or before the day where it is required to be paid under the provisions of this Chapter, interest shall be added to the amount of tax due. Such interest shall be computed from the due date until the tax is paid. The interest 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 or remitted.

B. Notwithstanding any provision of law to the contrary, for all taxes that become due on or after January 1, 2023, the rate of interest on any amount of outstanding tax shall not exceed one percent per month.

C. Notwithstanding any provision of this Section or of this Chapter, the interest on any amount of tax outstanding on a specific date shall be computed at the rate applicable on such date.