We are headquartered in Nashville, TN with business operations in Tennessee and Florida. I am CFO (glorified title) and new to the business and am not sure if we are being properly charged sales tax on our materials purchases or if we are required to charge any sales tax on our sales. We install new roofs, do re-roofs and roofing repairs. Many of our jobs include specialty roofing materials that are fabricated in our shop. It appears that we have never charged a customer any sales tax on our service jobs. I have also found that we have sold salvage/surplus roofing materials without charging sales tax.