Mississippi Code Title 91. Trusts and Estates § 91-25-19

(a) A person required under Section 91-25-17 to pay an estate tax greater than the amount due from the person under Section 91-25-5 or 91-25-7 has a right to reimbursement from another person to the extent that the other person has not paid the tax required by Section 91-25-5 or 91-25-7 and a right to reimbursement ratably from other persons to the extent that each has not contributed a portion of the amount collected under Section 91-25-17(b). The right to reimbursement includes the right to receive interest on the amount of the estate tax payment from the date of the payment to the date of reimbursement at the interest rate that would be charged during such period on an estate tax deficiency by the taxing authority that imposed the estate tax. The right of reimbursement also includes the reasonable costs of collection, including attorney's fees.

(b) A fiduciary may enforce the right of reimbursement under subsection (a) on behalf of the person that is entitled to the reimbursement and shall take reasonable steps to do so if requested by the person.