It’s not too bad as long as you’re not a dick about it. One year I marked myself as head of household instead of single. I’m not even sure why I did it. I only thought “huh, this saved a lot on my taxes”, and really had no idea what I was doing. They sent back a correction and how much i owed. I paid and that was it. Not scary at all.

Of course in today’s world all about spite and punishment I could imagine it being much worse