To appeal an IRS tax assessment, you file a written protest with the Independent Office of Appeals within 30 days of the letter proposing the change, using either a one-page Small Case Request or a Formal Written Protest depending on how much money is at stake. The filing itself is free, the conference that follows is informal, and roughly two-thirds of Tax Court cases settle through Appeals or IRS Counsel before ever reaching a judge. Interest keeps running while your case is pending, so timing matters.
The Notice That Starts Your Clock
Almost every appeal begins with one of two letters. The first is the “30-day letter” (typically Letter 525 or Letter 915). It reports the results of an audit, lists the specific adjustments the IRS proposes to your return, and gives you 30 days to either agree or request an Appeals conference. The letter states the deadline and the office to send your response to.
If the 30 days lapse without a response, the IRS issues a Statutory Notice of Deficiency, known as the “90-day letter” (Letter 3219 for mail audits, Letter 531 for in-person audits). This is a legal notice giving you 90 days from the mailing date to file a petition with the U.S. Tax Court, or 150 days if the notice is addressed to you outside the United States. Miss that deadline and the IRS assesses the tax and starts collection.
Responding to the 30-day letter is almost always the better move. It keeps you in the administrative system, which is cheaper and faster than court.
Do You Have Grounds to Appeal?
You need a genuine disagreement rooted in tax law or the facts of your return: the IRS misapplied a section of the Internal Revenue Code, misunderstood a deduction or income item, or made a computational error. You don’t need to be a tax expert. “I had documentation for that deduction and the auditor ignored it” is a legitimate factual dispute.
What the IRS will not entertain is a protest built on moral, religious, political, or constitutional objections to paying taxes. Filing a frivolous appeal has teeth: if a case reaches Tax Court and the court finds the position groundless or maintained mainly for delay, it can impose a penalty of up to $25,000 on top of the tax owed.
An appeal is also not a payment plan. If you agree you owe the tax but can’t pay, the right tools are an installment agreement or an offer in compromise, not a protest.
Small Case Request or Formal Written Protest?
Which document you file depends on the dollar amount for each tax period at issue.
If the total additional tax, penalties, and interest proposed for a given tax period is $25,000 or less, you can file a Small Case Request using Form 12203 (Request for Appeals Review). It’s a one-page form. You identify the changes you disagree with and briefly explain why. A few clear sentences per disputed item is enough.
If the amount exceeds $25,000 for any tax period involved, you must prepare a Formal Written Protest, and you must do so for all periods at issue, even the ones under the threshold. There is no pre-printed form. You write it as a letter that includes:
- A statement that you want to appeal the proposed changes.
- Your name, address, and daytime phone number.
- A list of every adjustment you dispute, the tax periods involved, and why you disagree with each one.
- The facts behind each disputed item: the transactions, the documentation you have, what actually happened.
- The legal authority supporting your position: Internal Revenue Code sections, Treasury Regulations, Revenue Rulings, or court decisions. You aren’t writing a legal brief, but pointing to the relevant authority strengthens your case.
- A signed perjury declaration reading: “Under penalties of perjury, I declare that I examined the facts stated in this protest, including any accompanying documents, and, to the best of my knowledge and belief, they are true, correct, and complete.”
If a representative prepares the protest for you, the declaration language shifts: the representative states either that the information is true to the best of their personal knowledge, or that they have no personal knowledge of it and are relying on your representations.
Filing on Time
The 30-day deadline is firm. Mail your protest or Small Case Request to the specific IRS office listed on the letter, not to a general IRS address. Send it by certified mail with a return receipt. That postmark is your proof if the IRS later claims it never arrived.
Once the IRS receives your protest, the file goes to the Independent Office of Appeals. You’ll eventually get a letter confirming receipt and giving you the name and contact information for your assigned Appeals Officer. The wait varies with case complexity and Appeals workload: sometimes a few weeks, sometimes several months.
What Happens at the Appeals Conference
The conference is informal. It can happen by phone, video, in person at an Appeals office, or by correspondence. Most are conducted by phone. There is no courtroom procedure, no dress code, no “Your Honor.” It’s a conversation, sometimes one call and sometimes a series of exchanges over weeks.
The Appeals Officer is walled off from the examiner who audited you. They evaluate cases on what the office calls “hazards of litigation”: how likely the IRS would be to win in court. If the officer concludes the government has a weak position on a particular issue, they have the authority to concede it or split the difference. That framing tells you how to present your case. Show the officer why the IRS would have trouble winning in front of a judge: where the examiner got the facts wrong, where the law supports you, where the record is thin on the government’s side.
The officer will have already reviewed your protest, the examiner’s report, and the underlying file. Bring supporting documents you haven’t already submitted if they help. Expect pointed questions and some pushback on weak points. That’s normal.
At the end, the officer proposes a resolution. Sometimes the IRS concedes entirely. Sometimes you concede. More often, both sides give ground. The officer has real authority to make these deals without checking back with the examiner.
Interest Keeps Running
Filing a protest does not pause interest on any unpaid tax. Neither does having your case pending in Appeals. The IRS charges interest on underpayments at a rate set quarterly, compounded daily. For the first quarter of 2026, that rate is 7 percent.
If you want to stop interest from piling up while you fight the assessment, you can make a cash deposit under Internal Revenue Code Section 6603. This is not a payment. It’s a deposit the IRS holds, and you can request it back in writing at any time if the dispute resolves in your favor. For interest purposes, the deposited amount is treated as if you had paid the tax on the date of the deposit. IRS guidance suggests that if you’ve received a 30-day letter, the deposit should be at least the proposed deficiency listed in the letter.
Whether to deposit is a judgment call. If you expect to win most of the dispute, it may not be worth it. If the disputed amount is large and the case could drag on for months, 7 percent annual interest adds up fast. Run the numbers.
How a Settlement Gets Documented
If you reach agreement with the Appeals Officer, the resolution gets recorded on one of two forms, and the choice matters.
A standard agreement form such as Form 870 lets both sides move on but includes no pledge against reopening. In theory the IRS could revisit the issue later, though this is rare in practice. It becomes effective when the IRS receives it.
Form 870-AD is stronger. It includes a mutual commitment that neither side will reopen the case. Appeals typically uses it when both sides have made meaningful concessions. It becomes effective when the Commissioner or a delegate accepts it, not simply when the IRS receives it. If you want maximum certainty that the settled issue stays settled, ask for Form 870-AD.
A formal closing agreement under Internal Revenue Code Section 7121 carries full statutory binding effect, but it’s rarely used at the Appeals level. For most taxpayers, Form 870-AD provides more than enough protection.
If the Dispute Is About Collection, Not the Assessment
The process above covers disputes over how much tax you owe. If the IRS has already assessed the tax and is now trying to collect through a lien, a levy, or a seizure, you have separate appeal rights: Collection Due Process (CDP) hearings and the Collection Appeals Program (CAP).
A CDP hearing is triggered when the IRS issues a Final Notice of Intent to Levy or files a Notice of Federal Tax Lien. You have 30 days to request a hearing with the Independent Office of Appeals. A timely request suspends collection while your case is pending, and if you disagree with the Appeals Officer’s determination you can petition the Tax Court for judicial review. You can even challenge the underlying tax liability in a CDP hearing if you never had a prior opportunity to dispute it.
CAP is faster and less formal, designed for straightforward disputes about liens, levies, or denied installment agreements. The tradeoff: CAP decisions carry no judicial review. If you lose in CAP, no court will hear you. Choose CAP only for low-stakes collection issues where speed matters more than preserving the right to go to court.
If Appeals Doesn’t Resolve It
If Appeals can’t settle your case or the offer is unacceptable, you still have options.
U.S. Tax Court. This is the most common next step because you can challenge the IRS without paying the disputed tax first. File a petition within 90 days of the date on your Statutory Notice of Deficiency (150 days if you’re outside the country). The filing fee is $60. The court’s simplified “S” procedure covers cases under $50,000. About two-thirds of Tax Court cases ultimately settle, many through Appeals, so filing a petition doesn’t necessarily mean going to trial.
Federal district court or the Court of Federal Claims. These courts handle tax refund suits, but you must pay the full disputed tax first, then file a claim for refund with the IRS. If the IRS denies the claim, or sits on it for six months without acting, you can sue the United States for a refund. This route makes sense in limited situations, such as when you want a jury trial (available only in district court) or when favorable precedent exists in your circuit but not in the Tax Court.
The refund suit route has a firm prerequisite: no court will hear your case unless you first filed a refund claim with the IRS. Skipping that step gets the lawsuit dismissed.
Getting Help
You don’t need a representative to handle your own appeal. Many taxpayers navigate the process alone, especially for straightforward factual disputes. For larger dollar amounts, multiple tax years, or legal questions about code interpretation, professional help can change the outcome.
To represent you before the IRS, a person must file Form 2848 (Power of Attorney and Declaration of Representative) and fall into one of several authorized categories. The most common are attorneys, certified public accountants, and enrolled agents. Officers and full-time employees can represent a business. Immediate family members can represent you. Enrolled actuaries and enrolled retirement plan agents have limited authority for specialized matters.
If you can’t afford representation, Low Income Taxpayer Clinics provide free or low-cost help with IRS disputes, including appeals. Eligibility generally requires income at or below 250 percent of the federal poverty guidelines. For a single individual in 2026, that’s $39,125 in the 48 contiguous states. Clinics also help taxpayers who speak English as a second language. The IRS publishes a directory of LITCs on its website, and the Taxpayer Advocate Service can connect you with one in your area.