Business Tax Classification 4 - for Contractors This video will discuss the unique registration and filing requirements for contractors who fall in business tax classification 4 in Tennessee. Click here to begin watching the video. May 30, 2019 19:55 Related articles What is a location ID? Federal corporate income tax returns are due on October 15 for the 2018 calendar year corporations that file an extension. Can a taxpayer filing a corporate federal tax return obtain a state extension for filing its F&E return through November 15, 2019? How do I choose the correct business tax classification for my business? What qualifies for industrial machinery exemption? Can the Tennessee Lottery Corporation withhold lottery winnings to offset a tax liability that the winner owes to the state?