If you disagree with what the IRS says you owe, you have two main ways to fight it without paying first: an administrative appeal to the IRS Independent Office of Appeals, and a petition to the United States Tax Court. Both are available, but each is locked behind a strict deadline printed on the IRS notice you received. Miss the deadline and your options shrink to paying the full amount and suing for a refund.
The Two Deadlines That Control Everything
Most disputes start with a letter from the IRS proposing changes to your return, such as a Letter 525 or a CP2000 notice. You have 30 days from the date on that letter to file a protest and request review by the Independent Office of Appeals.1Internal Revenue Service. Letters and Notices Offering an Appeal Opportunity Let that window close and the IRS moves ahead with its proposed changes and eventually issues a Notice of Deficiency.
The Notice of Deficiency, sometimes called the “90-day letter,” triggers the more consequential deadline. From the date the IRS mails it, you have exactly 90 days to file a petition in Tax Court, or 150 days if the notice is addressed to you outside the United States.2Office of the Law Revision Counsel. 26 USC 6213 – Restrictions Applicable to Deficiencies; Petition to Tax Court If you let this one pass, the IRS assesses the deficiency and starts collection, and your only remaining route is to pay in full and sue for a refund. That is why the Notice of Deficiency is often called your ticket to Tax Court.
Step One: Protest to IRS Appeals
How you request review depends on the amount at stake. If the total tax, penalties, and interest for each period is $25,000 or less, you can submit a small case request, which is essentially a short letter identifying the items you disagree with and why.3Internal Revenue Service. Appeals Process If any period exceeds $25,000, you must file a formal written protest.
A formal written protest needs to include:
- Your full name, address, and daytime phone number.
- A clear statement that you want to appeal the IRS findings to the Appeals Office.
- A copy of the IRS letter proposing the adjustment, along with the tax years involved.
- Each change you dispute, with your reasons for disagreeing.
- The specific facts supporting your position on each disputed item.
- Any tax law, Treasury regulation, or revenue ruling you rely on.
- Your signature under a declaration that the facts are true, correct, and complete under penalties of perjury.
These requirements come from IRS Publication 5.3Internal Revenue Service. Appeals Process Mail the protest to the address on the IRS letter that proposed the adjustment, and use certified mail so you have proof it arrived within the 30 days.
What Happens Inside an Appeals Conference
Once your protest lands, the case moves from the examiner who proposed the changes to an Appeals Officer, who acts as a neutral decision-maker separate from the audit team. Federal rules restrict the Appeals Officer from having behind-the-scenes conversations with the original examiner about the merits of your case unless you or your representative get a chance to participate.4Internal Revenue Service. Revenue Procedure 2012-18 – Ex Parte Communications Between Appeals and Other IRS Employees
The conference itself is informal and can happen by phone, video, or in person at a regional office. Unlike the original examiner, the Appeals Officer is allowed to weigh the government’s litigation risk and offer a compromise settlement based on how likely the IRS would be to win in court.5Taxpayer Advocate Service. Appeals Considers Risk of Going to Court (Hazards of Litigation) That gives you room to negotiate that you never had with the auditor.
If you reach agreement, you typically sign Form 870-AD, which waives restrictions on the IRS assessing the agreed amount. Once both sides sign, the settlement is generally final and you cannot relitigate the same issue later.6Internal Revenue Service. 8.6.4 Reaching Settlement and Securing an Appeals Agreement Form If you cannot agree, the IRS issues a Notice of Deficiency and the 90-day Tax Court clock starts.
Step Two: Petition the Tax Court
Tax Court is the only federal court where you can challenge a deficiency without paying it first. Your case starts when you file Tax Court Form 2, the simplified Petition, within 90 days of the mailing date on the Notice of Deficiency.7United States Tax Court. Guidance for Petitioners – Starting a Case The petition identifies you, the tax year at issue, and each error you believe the IRS made.
The filing fee is $60, payable by check, money order, or online. If you cannot afford it, you can submit an Application for Waiver of Filing Fee, which requires detailed financial information signed under penalty of perjury.8United States Tax Court. Court Fees You can file by mail to the Tax Court in Washington, D.C., or through the court’s electronic filing system.
You do not need a lawyer. Individuals are permitted to represent themselves, though you must follow all court rules, orders, and deadlines just as an attorney would.7United States Tax Court. Guidance for Petitioners – Starting a Case The court’s judges travel to about 60 cities to hold trial sessions, so most people can attend near where they live.9United States Tax Court. Places of Trial
The Small Tax Case Option
If the amount in dispute is $50,000 or less for any single tax year, you can elect the small tax case procedure, known as an S case.10Office of the Law Revision Counsel. 26 USC 7463 – Disputes Involving $50,000 or Less The procedures are simpler and the rules of evidence are relaxed, which helps people without lawyers present their case.
The trade-off is finality. A decision in an S case cannot be appealed by either side, and it sets no precedent for other taxpayers.10Office of the Law Revision Counsel. 26 USC 7463 – Disputes Involving $50,000 or Less If your dispute involves more than $50,000, or you want the ability to appeal an unfavorable ruling, proceed under the regular Tax Court rules instead. Regular cases follow the Federal Rules of Evidence, and either side can appeal the judge’s decision to a U.S. Court of Appeals.11Office of the Law Revision Counsel. 26 USC 7453 – Rules of Practice, Procedure, and Evidence
If You Missed the 90-Day Window
Losing the Tax Court deadline is not the end of the fight, but it changes the shape of it. You can pay the full assessed amount, file a refund claim with the IRS, and then sue for a refund in either a federal district court or the U.S. Court of Federal Claims.2Office of the Law Revision Counsel. 26 USC 6213 – Restrictions Applicable to Deficiencies; Petition to Tax Court District court offers a jury trial, which Tax Court does not. The Court of Federal Claims, based in Washington, D.C., decides cases without a jury. Both require that you first exhaust an IRS administrative refund claim.
For most people, this is the harder road. The full-payment requirement is exactly what Tax Court exists to avoid.
Fighting an IRS Levy: Collection Due Process
The routes above are for disagreeing with the tax the IRS says you owe. If your fight is instead about collection, when the IRS moves to levy your wages, bank accounts, or other property, a different process applies. Before levying, the IRS must send you written notice of its intent and tell you about your right to a Collection Due Process (CDP) hearing.12Office of the Law Revision Counsel. 26 USC 6330 – Notice and Opportunity for Hearing Before Levy
You have 30 days from that notice to request a CDP hearing by filing Form 12153. At the hearing you can raise whether the underlying tax was correctly assessed, whether you qualify for an installment agreement or offer in compromise, or whether the levy would create an undue hardship. If you disagree with the Appeals Officer’s determination, you have 30 days to petition Tax Court for judicial review.12Office of the Law Revision Counsel. 26 USC 6330 – Notice and Opportunity for Hearing Before Levy Collection is generally suspended while the CDP process is pending.
What a Fight Costs You in the Meantime
Interest does not pause while you argue. From the original due date of the return through the date you pay, the IRS charges interest at the federal underpayment rate, which stood at 7% per year, compounded daily, as of early 2026.13Internal Revenue Service. Interest Rates Remain the Same for the First Quarter of 2026 The rate resets quarterly, so a long dispute may see it move. Every month you spend in Appeals or Tax Court adds to the bill if you lose.
There is also a penalty aimed at bad-faith filings. If the Tax Court concludes that you filed your petition mainly to delay collection, that your position was frivolous, or that you skipped available administrative remedies, it can impose a penalty of up to $25,000.14Office of the Law Revision Counsel. 26 USC 6673 – Sanctions and Costs Awarded by Courts Good-faith disagreement about how much you owe is not what this penalty targets.
Getting Help You Can Afford
Tax attorneys typically bill somewhere between $200 and over $1,000 an hour. If that is out of reach, a Low Income Taxpayer Clinic may take your case for free or a nominal fee. LITCs serve taxpayers whose income does not exceed 250% of the federal poverty guidelines. IRS Publication 4134 lists every participating clinic by state.
Whether you hire someone or handle it yourself, respond to every IRS notice and court order on time. Missed deadlines cost more cases than weak facts.