To file a petition with the U.S. Tax Court, you submit three forms (Petition, Statement of Taxpayer Identification Number, and Request for Place of Trial) along with a copy of your IRS Notice of Deficiency and a $60 filing fee, either electronically through the court’s DAWSON system or by mail, within 90 days of the date the IRS mailed the notice. That deadline is the whole game. Miss it and the court loses authority to hear your case, no matter how right you are on the merits. Everything below assumes you’re still inside the window and works backward from there.
The 90-Day Deadline
Your right to petition begins with a Notice of Deficiency, sometimes called a “90-day letter.” The IRS sends it by certified or registered mail, and it proposes an additional tax you owe. Without that notice in hand, the Tax Court has no jurisdiction. The IRS also issues similar notices for collection actions, innocent spouse claims, and worker classification disputes, and each of those carries its own separate right to petition.
From the mailing date on the notice, you have 90 days to file. If the notice was addressed to you outside the United States, you get 150. The Tax Court has confirmed it cannot extend either deadline, even for good cause. If day 90 (or 150) lands on a Saturday, Sunday, or legal holiday in the District of Columbia, the deadline rolls to the next business day. That’s the only softening you’ll get.
Count carefully from the date on the notice itself, not the day you received it.
What Goes in the Petition Packet
The Tax Court publishes a petition kit on its website with three forms. All three go in together.
Form 2, the Petition itself. This is the main document. It asks for your name, mailing address, the city and state of the IRS office that issued the notice, and the specific tax years in dispute. The section that matters most is your statement of errors: what the IRS got wrong and the facts that support your position. Be specific about dollar amounts and the legal basis for each disagreement. Vague complaints or political arguments will get the petition rejected at the clerk’s desk. Redact your Social Security number and other personal identifiers from this form and from the notice you attach to it.
Form 4, Statement of Taxpayer Identification Number. This is the only place your full SSN or taxpayer ID goes. It’s kept separate from the public case file.
Form 5, Request for Place of Trial. You pick one city from roughly 70 locations nationwide. Small tax cases can request any listed city; regular cases are limited to cities not marked with an asterisk on the form. Choose the city closest to where you live or where your records sit.
Along with the three forms, enclose a copy of the IRS notice you’re challenging (with identifiers blacked out) and the $60 filing fee.
How to Submit It
DAWSON, the court’s electronic filing system, is the most common route. Create an account on the Tax Court website, upload the forms and attachments, and pay the fee online. You get an immediate confirmation of receipt and can track the case from there. A DAWSON filing is timely if it’s submitted by 11:59 p.m. Eastern time on the due date.
You can also file by mail. Under the timely-mailing rule, the U.S. postmark date counts as your filing date, so a petition postmarked on day 90 is timely even if it lands at the court a week later. The rule extends to certain designated private delivery services from FedEx, UPS, and DHL, but only specific service levels within each carrier qualify. Confirm the service you’re using is on the approved list before relying on it. If you mail the petition, include a check or money order for $60 payable to “Clerk, United States Tax Court.”
If you can’t afford the fee, the court accepts a hardship-based fee waiver application in place of payment. The petition kit points to this option.
Should You Elect the Small Tax Case Procedure?
If the disputed amount is $50,000 or less for any single tax year, you can elect “small tax case” (S case) treatment by checking a box on the petition. The court must agree to the election. S cases use relaxed evidentiary rules and streamlined hearings built for taxpayers without lawyers.
The trade-off is real: an S case decision is final for both sides, cannot be appealed, and cannot be cited as precedent anywhere else. If your dispute turns on a genuinely difficult legal question, or the amount at stake sits near the $50,000 ceiling, the regular procedure may be worth the added formality. You can withdraw the S case designation any time before trial begins, either on your own motion or the court’s. Once trial starts, you’re locked in.
What Happens After You File
The IRS has 60 days after the court processes your petition to file an “Answer,” admitting or denying each of your claims and raising any additional defenses. That exchange narrows the dispute.
Many cases then go to the IRS Independent Office of Appeals for settlement discussions. Appeals officers have authority to compromise, and most Tax Court cases settle before trial. Treat that stage seriously.
If the case doesn’t settle, you and the IRS attorney are required to stipulate to every fact where agreement can fairly be reached, including documents and background facts. Stipulations are filed in writing and carry the weight of evidence proven at trial. The court then issues a trial notice and a Standing Pretrial Order setting deadlines for exchanging documents, identifying witnesses, and filing pretrial memoranda. Follow the pretrial order exactly. Judges have little patience for parties who miss its deadlines or arrive unprepared.
Who Has to Prove What
In most Tax Court cases, you carry the burden of proof. That means arriving with records, receipts, and documentation for every position you’re taking. Many self-represented petitioners lose here: they know the IRS is wrong but cannot produce the paperwork to show it.
The burden can shift to the IRS in specific situations. If you introduce credible evidence on a factual issue, keep all required records, and cooperate with reasonable IRS information requests, the government must prove its position. The IRS also carries the burden when it alleges civil fraud, when it uses statistical data about unrelated taxpayers to reconstruct your income, and when it raises new issues or claims a larger deficiency than what appeared in the original notice.
Plan as if the burden will stay with you. It usually does.
Interest Doesn’t Stop While You Litigate
Filing the petition stops the IRS from collecting the disputed amount, but interest continues to accrue on any tax the court eventually finds you owe, calculated from the original due date of the return until you pay in full. The IRS underpayment interest rate is set quarterly. If there’s a portion of the tax you know you’ll end up owing regardless of the outcome, you can make a voluntary payment during the case to stop interest from building on that piece.
Positions That Will Get You Penalized
The Tax Court can impose a penalty of up to $25,000 if it finds your petition was filed mainly to delay collection, that your position is frivolous or groundless, or that you unreasonably bypassed available IRS administrative remedies. Arguments that the income tax is unconstitutional, that wages aren’t income, or that filing is voluntary are textbook frivolous positions. Raising them won’t just lose the case; it can add thousands to what you owe.
If the 90 Days Have Already Passed
Once the deadline runs, the Tax Court will dismiss the petition for lack of jurisdiction and the IRS can assess the full amount and begin collection. You still have a path, but a more expensive one: pay the disputed tax in full, file a refund claim with the IRS, and if the claim is denied (or the IRS doesn’t respond within six months) sue for a refund in a U.S. District Court or the U.S. Court of Federal Claims. The pay-first requirement in those forums is exactly what a timely Tax Court petition lets you avoid.
Free and Low-Cost Help
You don’t need a lawyer to file or to represent yourself at trial, and the small tax case procedure is designed with self-represented taxpayers in mind. Low Income Taxpayer Clinics provide free or low-cost representation to qualifying taxpayers in IRS disputes, including Tax Court cases. For 2026, individual taxpayers earning up to $39,900 (or $82,500 for a family of four) in the 48 contiguous states generally qualify, though each clinic sets its own criteria. IRS Publication 4134 and the Taxpayer Advocate Service website list clinics by location. Many clinics also assist taxpayers who speak English as a second language.