Most tax problems are civil and stay civil. A narrow band crosses into criminal territory - and recognizing the line, and the moments that demand counsel immediately, is knowledge worth having before you need it.
Where the Line Actually Sits
Owing money is not a crime. Filing late is not a crime. Even years of non-filing resolve civilly in the overwhelming majority of cases. The criminal band is conduct: willful evasion, false documents, hidden offshore accounts, payroll withholding taken and spent, obstruction of the process itself. The IRS pursues a few thousand criminal cases a year against tens of millions of delinquent accounts - and the cases it picks share the concealment thread, which is why voluntary correction before detection is the strongest protection in the system.
The Moments That Demand Counsel Now
Two people presenting credentials reading Special Agent: that is IRS Criminal Investigation, the conversation is evidence, you owe them nothing beyond identifying yourself, and the only correct response is polite silence plus a lawyer's phone number. An active audit that abruptly goes silent - examiners suspend when fraud gets referred. Questions shifting from what happened to why and what you knew. Summonses landing on your banks and associates. Any of these moves the case to attorney territory immediately - and specifically attorney territory, because attorney-client privilege holds in criminal matters where accountant communications can be compelled. The accountant who prepared the returns in question may become a witness; the attorney never does.
What Defense Actually Looks Like
Early-stage criminal tax defense is mostly prevention: the privileged assessment of actual exposure, the voluntary disclosure lanes that trade defined penalties for protection against referral, the conduct of the civil case so it never generates the referral at all. I came to tax law from a public defender's office - the government side of the table is familiar ground - and the first move in every version of this situation is the same: say nothing, sign nothing, and have the privileged conversation before anyone else hears the story. That conversation is free here, and privileged from the first minute.