Any law to the contrary notwithstanding, any retailer, who relies in good faith on any state utility gross receipts tax exemption number that has been authorized by the Department of Revenue and the exemption claim has been made on a form provided or approved for use by the Department of Revenue, when a state tax exemption number holder violates the tax exempt privileges or uses the number illegally, shall not be liable to the Department of Revenue or others for the utility gross receipts tax on sales to the purchaser.
Ala. Code § 40-21-88 (1975)