Your fee for using TurboTax is not based on the amount of your refund. Your fee is based on which version of the software was used to prepare your tax return. Many users who use paid versions of the software OWE tax to the IRS----that does not mean they use TT software for free.
Use this IRS site for other ways to file for free. There are 8 free software versions available from the IRS Free File site
https://apps.irs.gov/app/freeFile/
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
