Miss. Code Ann. § 27-9-29: Miss. Code Ann. § 27-9-29

The commissioner shall grant the person paying the tax a temporary receipt upon the payment of the amount of tax shown to be due on the return or any part thereof, but all returns shall remain subject to investigation and audit by the commissioner, who shall furnish to the person paying the tax or to the executor of the estate a full, final and complete receipt after said investigation has been completed and any additional tax found due has been paid. The commissioner shall have a period of four (4) years after the filing of said return within which time to make such investigation but in the event that the executor shall furnish to the commissioner a statement from the federal government that all federal estate taxes have been paid and giving the value of the property reported to and accepted by the federal government, the commissioner may at that time furnish the executor a final receipt if all estate taxes have been paid to the State of Mississippi upon the same basis of valuation as paid to the federal government. All valuations accepted by the federal government shall be prima facie correct for the purpose of the administration of this chapter, and the duty is placed upon the executor of the estate to furnish to the commissioner a copy of all valuations changed or accepted by the federal government for the purpose of administering the federal estate tax statute.

In the event that no estate tax return is filed, the commissioner shall have a period of ten (10) years from the due date of the return to investigate said estate and to assess estate tax.