If it comes to the issue of inadequate withholdings or inadequate estimated payments, the first conversation probably needs to be with the return preparer. That’s the person who’s giving you the advice that whatever you are going to file is going to have an unexpected liability based on the shortfall in estimated payments.
Beyond that, I think it would be prudent to reach out to other tax professionals. The return preparer could be this, or you would consider engaging a tax attorney to see guidance on how to approach the problem. I would say it’s probably premature at that point to reach out and engage with the government agencies because until that return has been filed and any late payments, estimated tax payment and penalties have been assessed, there isn’t much that can be proactively done.
That being said, I would say as a general rule the most important thing is not to forget the filing obligation. We have seen it and assisted clients before who have fallen victim to the idea that they shouldn’t file if they can’t pay, and unfortunately, that turns a bad situation worse.
If it came down to the choice, file, have the assessment with the penalty, have the assessment, whatever small penalties for failure to make estimated payments might be accompanying that, and then work on it. Installment agreement, offer and compromise, penalty abatement, full pay within a period like a deferral, but failing to file only would exacerbate the situation.