I know from my own experience that there are problems with income tax software. A few years ago, I tried to use a commercial software package. Part way through I spotted a mistake. The software omitted mention of one key fact. I could see the problem but I couldn't correct it, so I did my taxes by hand. Last year I used free software by H&R Block, and it worked fine. It even suggested helpful things that I was not aware of. Yesterday I started doing my income tax again with H&R Block free software. Part way through, it told me that it lacks an online version one of the forms I need to use, and it told me to go to an H&R Block office (and pay). Today I'm going to H&R Block. A word to the wise: The form not available online is for deducting money paid into a flexible spending account for health care.