Any person, firm or corporation contracting with a nonresident person, firm or corporation engaged in a business or service taxed under this article shall withhold payment in sufficient amount to cover taxes assessed by this article in the final settlement of such contracts until the receipt of a certificate from the Collector and Treasurer to the effect that all taxes levied and accrued under this article against the contractor have been paid.
If any person, firm or corporation fails to withhold as provided herein, he shall be personally liable for the payment of all such taxes, and the same shall be recoverable by the Collector and Treasurer by appropriate legal proceedings. (1967 Code Sec. 6-21.6)