Ala. Code § 40-23-82
If any retailer liable for an amount of tax herein required to be collected shall sell out his business or stock of goods or shall quit the business, he shall make a final return and payment within 15 days after the date of selling or quitting business. His successor, successors or assigns, if any, shall be required to withhold sufficient of the purchase money to cover the amount of such taxes herein required to be collected and interest or penalties due and unpaid until such time as the former owner shall produce a receipt from the department showing that they have been paid, or a certificate stating that no amount is due. If the purchaser of a business or stock of goods shall fail to withhold purchase money as above provided, he shall be personally liable for the payment of the amount of taxes herein required to be collected by the former owner, interest and penalties accrued and unpaid by any former owner, owners or assignors.
Ala. Code § 40-23-82 (1975)