Pursuant to Miss. Code Ann. Section 27-7-43 a taxpayer will only be allowed to change an accounting period when it has received approval from the Commissioner. If permission is granted by the federal government to change the accounting period, then state permission is automatic provided the taxpayer attaches a copy of the written federal approval to the first state return filed for the new period. If the Commissioner determines that such change in accounting period results in an understatement of income, the Commissioner will deny the final approval.
35 Miss. Code. R. 3-01-02-104