Ala. Code § 40-21-19
If at any time after March 1 of any year the Department of Revenue shall not have in its possession satisfactory data upon which to base an estimate of the value of the property with the assessment of which it is charged or from any other cause it is not able to make or complete any assessment, it shall have power to call upon any officer or agent of any person, firm, or corporation, or upon any receiver or trustee in charge of the property of any person, firm, or corporation for any records, books, or documents of any description pertaining to the business of any such person, firm, or corporation for the answers to any interrogatories which it may deem necessary to an intelligent discharge of its duties; and it shall also have power to require the attendance of any officer of any corporation or any other person where the testimony of such officer or person may to it seem material.
Ala. Code § 40-21-19 (1975)