Every person subject to the taxes levied in this Article who, on the effective date of a tax increase under this Article, has on hand any tobacco products must file a complete inventory of the tobacco products within 20 days after the effective date of the increase, and must pay an additional tax to the Secretary when filing the inventory. The amount of tax due is the amount due based on the difference between the former tax rate and the increased tax rate. (1969, c. 1075, s. 2; 1973, c. 476, s. 193; 1991, c. 689, s. 263; 2009-451, s. 27A.5(b).)