> the IRS doesn't consider accidental mistakes as fraud. A case for intention has to be made before the IRS actually charges you with a crime.
It's relatively easy to screw up your taxes by misentering a number into the paid software as well. The various guarantees the paid software people offer don't cover this sort of situation. I don't think this is really a factor.
Do you think if that happened while using Intuit software, they are going to pull intuit into court? When you prepare your taxes using software, it all looks the same once the IRS receives it. It will show up as self prepared. If you pay a CPA to do it, then they also sign the return. But in either case, you will be responsible for underpaying your taxes and will have to make up the difference. I doubt any of the software companies offer any kind of guarantee.
The big tax companies do offer some guarantees of the accuracy of their calculations.
Which is probably not the kind of mistake you’ll have on your taxes anyway. Basic arithmetic is easy. And if you do make these mistakes it’s not likely the IRS does anything more than correcting it. But it’s more than no guarantee.