Miss. Code Ann. § 27-35-517: Miss. Code Ann. § 27-35-517

(1) The assessment when made and completed shall remain open for thirty (30) days for inspection in the offices of the Department of Revenue and be subject to objections by the railcar companies for the same time period. The Board of Tax Appeals shall hear all objections, and it may increase or decrease any assessment if such action appears to be necessary and proper.

(2) Any objection shall be in writing and filed with the Executive Director of the Board of Tax Appeals within the thirty-day period set out in subsection (1) of this section for objections. At the time of filing the objection with the Executive Director of the Board of Tax Appeals, the taxpayer shall also file a copy of his written objection with the Department of Revenue.