Ala. Code § 11-22-13

The corporation, the property and income of the corporation, all bonds issued by the corporation, the income from such bonds, conveyances by or to the corporation and leases, mortgages and deeds of trust by or to the corporation shall be exempt from all taxation in the State of Alabama. No sales, use, license or excise tax may be imposed on any corporation in respect of the privilege of engaging in any of the activities authorized by this chapter.