Ala. Code § 40-22-6
If any mortgage, deed of trust, contract of conditional sale, or other instrument of like character heretofore or hereafter filed for record in any probate office of this state which was or shall be given to secure the payment of any debt incurred to a corporation, organization, or institution now or hereafter exempt by law from the payment of the recording privilege tax imposed by Section 40-22-2 and upon which such recording privilege tax has not been previously paid has been heretofore or be hereafter transferred to a person, corporation, organization, or institution not exempt from payment of such tax and such transfer is presented for record within this state, such transfer shall be received for record upon payment of the privilege tax imposed by said section upon the then unpaid balance of the secured debt and the recording fees of the probate judge.
Ala. Code § 40-22-6 (1975)