La. Revenue and Taxation § 47:1990
The tax commission may change or correct any and all assessments of property for the purpose of taxation, in order to make the assessments conform to the true and correct valuation, not to exceed its actual cash value. Such change or correction may be made by the tax commission at any time before the taxes levied have actually been paid.
In order to correct or change any such assessment, it shall only be necessary for the tax commission to issue written instructions to the assessor to make the change upon the assessment roll, and in the event the assessment roll has been delivered to the tax collector, then to direct the tax collector to make such change upon the tax roll in his possession and to collect taxes according to such change. Whenever the tax commission shall make any change or correction in an assessment, it shall at the same time forward to the auditor a copy of the instructions furnished to the assessor or tax collector. A copy of these written instructions shall be forwarded by the tax commission to the taxpayer by registered mail, and such written instructions, together with the return receipt of the taxpayer therefor, shall be sufficient notice of such change.
The written instructions issued as above provided by the tax commission to the tax collector shall authorize him to collect all taxes according to such change and shall be his authority to make the necessary deduction or increase on his tax roll and in his settlement for taxes with the auditor.
La. Revenue and Taxation § 47:1990