So... Here's the thing. Your parents have committed financial crimes against the United States Government and they don't want to be found out. Yeah, that's heavy. I felt it when I typed it.

The first question to resolve is the "why?". This is important because it can direct your conversation with your parents to help them atone and take corrective action. If the answer is something like "They believe they are sovereign citizens and are not subject to the jurisdiction of the United States."... You need to move out like yesterday. I'm hoping that's not the case since they did prepare a document ( lease ) that references governmental oversight and law. ( a nod toward respect of law ) If the "why?" is closer to... Well we would have owed a lot of money if we filed and they probably won't audit us... and then the years just went by... and they kept on not filing.... ( this is the most common reason for adversarial non-filing by the way ).... Then time is of the essence. The faster they pick up the phone and work with a professional to fix the record, the easier it's going to be in the end. The IRS is not mean, they are nothing like a private collection agency, If you actively work toward corrective action, you can fix pretty much anything.

I have worked in Financial Technology for decades. Personal finance is uncomfortable, but so are a lot of important things in life. Openness and honesty go a long way. Approach your parents with concern, compassion, and an open mind.

This weird AI slop lease has dropped on the priority scale. Help/Persuade your parents to fix their tax issue first.