Miss. Code § 27-7-41
Except as otherwise provided in this section, returns of individuals, estates, trusts and partnerships shall be filed on or before the 15th day of the fourth month following the close of the fiscal year; or if the return is filed on the basis of a calendar year, it shall be filed on or before April 15 of each year. Except as otherwise provided in this section, returns of corporations shall be filed on or before the 15th day of the third month following the close of the fiscal year; or if the return is filed on the basis of a calendar year, it shall be filed on or before March 15 of each year. For tax years beginning after December 31, 2015, the date for filing a return under this section shall be the same as the date provided for filing the corresponding federal return.
If the date for filing any report, claim, tax return, statement, remittance, or other document falls upon a Saturday, Sunday or legal holiday, the filing shall be considered timely if performed on the next business day.
All returns shall be made to the commissioner.
Miss. Code § 27-7-41