What if I make a mistake filing my tax return on TNTAP? A taxpayer can amend any return filed electronically online. March 31, 2017 18:50 Related articles Can I amend a filed return in TNTAP? Can I change a return in TNTAP? Will the state issue a refund in the event of an overpayment? How are penalties and interest computed? How do I reach the Tennessee Department of Revenue?