Louisiana Revised Statutes Tit. 47, § 305.11. Exclusions and exemptions; contracts prior to and within ninety days of tax levy

A. No new or additional sales or use tax shall be applicable to sales of materials or services involved in lump sum, unit price, fixed fee, or guaranteed maximum price construction contracts entered into and reduced to writing prior to the effective date of the statute or ordinance levying same or to sales or services involved in such contracts entered into and reduced to writing within ninety days thereafter, if such contracts involve contractual obligations undertaken prior to such effective date and were computed and bid on the basis of sales taxes at the rates effective and existing prior to such effective date.

B. This Section shall apply to sales and use taxes now or hereafter levied by the state of Louisiana or by any parish, municipality or other political subdivision thereof, whether such levy is under authority of general or special laws of the state or under powers granted in local charters or under any other authority or grant of the power to levy and collect sales or use taxes.