A.(1)(a) Except as otherwise provided in Subsection B of this Section, any taxpayer protesting the payment of any amount found due by the secretary of the Department of Revenue, or the enforcement of any provision of the tax laws in relation thereto, shall remit to the Department of Revenue the amount due and at that time shall give notice of intention to either file suit or file a petition with the Board of Tax Appeals for purposes of recovery of such tax.

            (b) In the case of sales or use taxes that are required to be collected and remitted by a selling dealer as provided for in La. Rev. Stat. 47:304, the purchaser, in order to avail himself of the alternative remedy provided by this Section, shall remit protested sales or use tax to the selling dealer, and shall retain copies of documentation evidencing the amount of the sales or use tax paid to the dealer on the transactions. On or before the twentieth day of the month following the month of the transactions on which the selling dealer charged the tax, the purchaser shall inform the department by certified mail or other reasonable means of the dates and amounts of the protested taxes that were charged by the selling dealer, and shall give notice of the purchaser’s intention to either file suit or file a petition with the Board of Tax Appeals for purposes of recovery of the tax.

            (2) Upon receipt of this notice, the amount remitted to the Department of Revenue or the amount of protested taxes that have been paid to the selling dealer shall be placed in an escrow account and held by the secretary or his duly authorized representative for a period of thirty days. If suit is filed for recovery of the tax within the thirty-day period, or if a petition is filed with the Board of Tax Appeals for recovery of the tax paid within the thirty-day period, the funds in the escrow account shall be further held pending the outcome of the suit, the petition, or an appeal therefrom.

            (3) If the taxpayer prevails, the secretary shall refund the amount to the claimant, with interest at the rate established pursuant to La. Rev. Stat. 13:4202(B) from the date the funds were received by the Department of Revenue or the due date, determined without regard to extensions, of the tax return, whichever is later, to the date of such refund. Payments of interest authorized by this Section shall be made from funds derived from current collections of the tax to be refunded.

            (4) There shall be no penalty for underpayments of estimated tax with regard to amounts paid under protest and such amounts paid under protest are not required to be paid until the due date of the return determined without regard to extensions.

            B. For income and corporation franchise tax purposes, in instances where the payment of tax under protest is required to be made before the amount of tax due is determinable, the taxpayer shall have thirty days from the due date of the tax return, or the extended due date of such return if applicable, to file suit or a petition with the Board of Tax Appeals for the recovery of such tax. If suit or a petition is filed within the thirty-day period and the taxpayer prevails, the secretary shall refund the amount to the claimant, with interest at the rate established pursuant to La. Rev. Stat. 13:4202 computed pursuant to La. Rev. Stat. 47:287.657 or La. Rev. Stat. 47:617 in the case of corporation taxes or La. Rev. Stat. 47:115 in the case of individual income tax.

            C. This Section shall afford a legal remedy and right of action in the Board of Tax Appeals as provided by law, or in any state court having jurisdiction of the parties and subject matter, for a full and complete adjudication of any and all questions arising in the enforcement of this Subtitle as to the legality of any tax accrued or accruing or the method of enforcement thereof. In such action, service of process upon the secretary shall be sufficient service, and he shall be the sole necessary and proper party defendant in any such suit.

            D. This Section shall be construed to provide a legal remedy in the Board of Tax Appeals or the state courts in case such taxes are claimed to be unconstitutional under any provision of the United States Constitution or Constitution of Louisiana, including an unlawful burden upon interstate commerce, or the collection thereof, in violation of any Act of Congress or the United States Constitution, or the Constitution of Louisiana.

            E. Upon request of a taxpayer and upon proper showing by such taxpayer that the principle of law involved in an additional assessment is already pending before the courts for judicial determination or pending before the Board of Tax Appeals, the taxpayer, upon agreement to abide by the decision of the courts, the Board of Tax Appeals, or by a final judgment of a court upon a timely appeal of a decision of the Board of Tax Appeals, may remit the additional assessment under protest, but need not file an additional suit or petition. In such cases, the tax so paid under protest shall be placed in an escrow account and held by the secretary until the question of law involved has been determined by the courts, the Board of Tax Appeals, or by a final judgment of a court upon a timely appeal of a decision of the Board of Tax Appeals, and shall then be disposed of as therein provided.

            Acts 1991, No. 558, §1; Acts 1997, No. 270, §1; Acts 1997, No. 658, §2; Acts 1999, No. 200, §1, eff. Oct. 1, 1999; Acts 2014, No. 198, §1, eff. July 1, 2014; Acts 2015, No. 210, §1, eff. June 23, 2015; Acts 2019, No. 365, §1, eff. Nov. 18, 2019.