The person paying the taxes is not always expected to understand exactly how the tax code applies to them. IANAL but I think that when you hire a human tax acco

The person paying the taxes is not always expected to understand exactly how the tax code applies to them. IANAL but I think that when you hire a human tax accountant, their saying that your return is legally sufficient for you to testify that you are entitled to your return as filed. I don't know how that would apply to tax software, but I imagine that for purposes that TurboTax is appropriate for, saying "well TurboTax, a widely used and generally respected accounting tool generated this return, so I believe that it is correct," would be sufficient. Of course if it turned out that you were not entitled to the full refund you filed for, you would still be liable to pay back the difference, but you wouldn't be assessed an additional fine. Again IANAL, this is how I expect the law would work, not necessarily how it actually works.