When the IRS decides you owe more tax, it sends a Notice of Deficiency - the 90-day letter. That notice is your ticket to the United States Tax Court, the only court in America where you can challenge a tax assessment before paying a dime of it.

Miss the 90 days and the option is gone. The tax gets assessed, collection begins, and your only judicial path becomes paying the tax in full and suing for a refund in district court. For most people, that is no path at all.

Why Tax Court Is Different

Tax Court judges hear nothing but tax cases. There is no jury. The rules of evidence are relaxed compared to district court, and the court has a long tradition of giving self-represented taxpayers some latitude. But the IRS is represented by Chief Counsel attorneys who do this every day, and the petition itself has formal requirements that trip people up.

Here is the part the IRS does not advertise: the vast majority of Tax Court cases settle before trial. Filing a petition moves your case out of the hands of the auditor who decided against you and into the hands of IRS Appeals and Chief Counsel, who evaluate hazards of litigation. Issues that were dead on arrival during the audit suddenly become negotiable when a judge might rule on them.

The Deadline Is Not Flexible

The 90-day deadline (150 days if the notice is addressed to someone outside the country) is jurisdictional in nature, and the Tax Court polices it strictly. It runs from the date on the notice, not the date you opened the envelope. There is no extension for good cause, no extra week because you were in the hospital, no mercy for the letter that sat in a stack of mail.

If you have a Notice of Deficiency in hand, count the days today. If you are inside the window, you have leverage. If the deadline is close, a petition can be filed quickly to preserve your rights while the real work happens afterward.

Admitted and Ready

I am admitted to practice before the United States Tax Court, and admission is national - it does not depend on any state bar. Whether the right move is filing a petition, working the case through Appeals, or both, the analysis starts with that notice in your hand. Send it to me before the clock runs out.