Ala. Code § 40-21-101
It is the intention of the Legislature of Alabama that the tax herein levied shall be supplemental to and complementary with the utility gross receipts tax so as to prevent discrimination in the effect of the utility gross receipts tax upon either intrastate or interstate commerce. It is the intention of the Legislature of Alabama that the tax herein levied shall apply to purchases of utility services from any utility. With respect to every tax exemption which may be enacted into law subsequent to the enactment of this article, there shall be a presumption that such exemption does not apply to the tax herein levied unless the statute containing such exemption shall make specific reference to this article and shall clearly show a legislative intention to make such exemption applicable to the tax herein levied.
Ala. Code § 40-21-101 (1975)