Ala. Code § 40-15-5
In the event that the federal authorities shall, after the filing of the return with the Department of Revenue, increase or decrease the amount of the federal estate taxes as a result of appeal or otherwise, an amended return shall be filed with the Department of Revenue showing all the changes made in the original return and the amount of final increase or decrease in the federal estate tax. If the amended return shall show an increase in the amount of the federal estate tax, the Department of Revenue shall assess against and there shall be payable in respect to said estate any deficiency in the tax theretofore paid or assessed. If the amended return shall show a decrease in the federal estate taxes, the Department of Revenue, on receipt of an appropriate certificate of refund, abatement or recovery, shall forthwith certify the amount of such refund found to be due to such estate to the Comptroller, who, upon receipt of such certificate of refund due, shall issue his warrant for the amount shown in said certificate, payable to the person legally authorized to receive such refund, such payment to be made from the general state funds.
Ala. Code § 40-15-5 (1975)