A taxpayer doing business in Tennessee that has substantial nexus in this state must register and file a franchise and excise tax return (FAE170). However, if it qualifies for the protection afforded by Public Law 86-272, it is only subject to the franchise tax and is not subject to the excise tax. In that situation, the taxpayer should check the box on page 1 of FAE170 indicating Public Law 86-272 and then complete only the franchise tax portion of the return.
Reference: Tenn. Code Ann. § 67-4-2004(49).