How do I get a username and password to file business tax online? Before you can file business tax online, you will need to sign up for a TN.gov username and password. This can be done from the business tax online filing home page. March 04, 2017 23:01 Related articles How do I file business tax online? I forgot my password for filing business tax online. What do I do? How do I manage additional login IDs? What is my business tax classification? How do I renew my business licenses? My local clerk said I would have to renew through the Department of Revenue.