A tax appeal is a formal process for challenging a tax bill or assessment you believe is wrong, whether the decision came from the IRS after an audit or from a local assessor valuing your home. Every taxpayer has the right to dispute these decisions through an independent administrative review before going to court.1Internal Revenue Service. Taxpayer Bill of Rights 5: The Right to Appeal an IRS Decision in an Independent Forum The catch is timing: filing windows are often 30 to 90 days, and missing one usually forfeits the right to challenge the bill at all.
What You Can Actually Appeal
An appeal needs grounds — a specific, supportable reason the assessment was legally or factually wrong. General frustration with your tax bill will not qualify. Most valid appeals fall into one of a few patterns.
Property Overvaluation or Unequal Assessment
Property tax appeals usually argue that your assessed value is higher than what the property would sell for on the open market. If the county assessed your home at $400,000 but comparable homes nearby are selling for $340,000, you have a basis to appeal. A related ground is unequal assessment: your property is valued at a higher percentage of market value than similar properties in your area, even if the dollar figure by itself looks defensible.
Denied Deductions, Credits, or IRS Errors
Federal income tax appeals often follow an audit in which the IRS disallows deductions or credits you claimed. A home office deduction, for example, may be rejected because the IRS decides your workspace failed the exclusive-use requirement.2Internal Revenue Service. How Small Business Owners Can Deduct Their Home Office From Their Taxes Disputes also arise from math errors, misclassified income, or the wrong tax rate being applied. The appeal succeeds by showing the IRS either misunderstood the facts or misapplied the law.
Missed Exemptions
When a taxing authority fails to apply an exemption you qualify for — a homestead credit, a veteran’s reduction, a senior freeze — your bill comes out higher than it should. These errors often happen during ownership transfers or annual record processing, and clear proof of eligibility usually leads to a straightforward correction.
The Deadlines That Control Everything
Tax appeal deadlines are enforced strictly. A day late generally means the right to challenge is gone, so treat every date on your notice as a hard cutoff.
Federal Income Tax: 30 Days, Then 90
After an audit, the IRS typically first sends a “30-day letter” proposing adjustments. You have 30 days to request an administrative appeal with the IRS Independent Office of Appeals, a less formal step that often resolves the dispute without a court.3Internal Revenue Service. Preparing a Request for Appeals
If that does not resolve things, the IRS issues a formal Notice of Deficiency, sometimes called a “90-day letter.” You then have exactly 90 days from the mailing date to file a petition with the United States Tax Court, or 150 days if the notice is addressed to you outside the United States.4Office of the Law Revision Counsel. 26 U.S. Code 6213 – Restrictions Applicable to Deficiencies; Petition to Tax Court The IRS cannot extend this period. Miss it, and the tax is assessed without your having a chance to challenge it in Tax Court before paying.
Collection Actions: 30 Days
If the IRS sends notice of intent to levy your assets or files a federal tax lien, you have 30 days from the date of the notice to request a Collection Due Process hearing.5Internal Revenue Service. 8.22.4 Collection Due Process Appeals Program Miss the 30-day window and you can still request an equivalent hearing within one year, but you lose certain protections, including the ability to petition Tax Court afterward.
Property Tax: Check the Notice
Property tax windows vary by jurisdiction. Many localities open a filing period shortly after assessment notices go out and keep it open somewhere between 30 and 120 days. The assessment notice itself will list the deadline and the office where you file, so read it the day it arrives.
Who Has to Prove What
In most tax appeals, you carry the initial burden. The government’s assessment is presumed correct, and it is up to you to show, by a preponderance of the evidence — more likely than not — that the assessment is wrong.
In federal court proceedings, the burden can shift to the IRS under specific conditions. If you introduce credible evidence on a factual issue, have substantiated all items in dispute, kept proper records, and cooperated with reasonable IRS requests, the IRS then has to prove its position.6Office of the Law Revision Counsel. 26 U.S. Code 7491 – Burden of Proof The IRS also bears the burden whenever it reconstructs your income using only statistical data from other taxpayers, and it must demonstrate the basis for any penalty it asserts.
What You File, and What You File It With
IRS Appeals
For an IRS dispute where the total tax, penalties, and interest for each period is $25,000 or less, you can file a small case request using IRS Form 12203, Request for Appeals Review.7Internal Revenue Service. Form 12203 – Request for Appeals Review The form asks for your taxpayer identification number, the tax periods, the specific changes you disagree with, and your reasons.
If any period exceeds $25,000, you have to file a formal written protest. It must include your name, address, and phone number; a statement that you want to appeal; a copy of the letter proposing the adjustment; a list of the disputed items with supporting facts; any legal authority you rely on; and your signature under penalties of perjury.8Internal Revenue Service. Appeals Process Attach a copy of the original notice either way.
Property Tax Appeals
The strongest evidence for a property appeal is comparable sales data — recent sale prices of similar properties in your area. An independent appraisal from a certified professional adds credibility and generally costs several hundred dollars. Photographs documenting damage, deferred maintenance, or other value-reducing conditions help. Pull together receipts, prior assessment notices, and any records showing how the assessor arrived at the disputed value.
Send your completed appeal package via certified mail with a return receipt. Online portals are increasingly available, but certified mail is still the safest proof of a timely filing.
What Happens After You File
For federal appeals, an Appeals officer who was not involved in the original audit is assigned to your case. That officer typically contacts you within 45 days by mail to schedule an informal conference.9Internal Revenue Service. Here’s What to Expect After Requesting an Appeal of a Tax Matter If you have not heard anything after 120 days, contact the IRS exam or collection office you last worked with. The conference is less formal than court: you can present your case by phone, video, or in person, and the officer evaluates the facts against the applicable law.
Property tax hearings before a local board of review or equalization follow a similar pattern. You present evidence and testimony, the assessor may respond, and the board issues a decision. These hearings are usually brief and do not require an attorney, though you may bring one.
If you win, the tax bill is adjusted and any overpayment is refunded. The IRS is required by statute to pay interest on overpayments from the date of the overpayment until shortly before the refund check is issued.10Office of the Law Revision Counsel. 26 U.S. Code 6611 – Interest on Overpayments
If the Administrative Appeal Fails
If the IRS issues a Notice of Deficiency, you can petition the United States Tax Court within the 90-day window. The filing fee is $60.11United States Tax Court. Court Fees Tax Court lets you challenge the IRS before paying the disputed amount, an advantage over courts that require you to pay first and sue for a refund.
For disputes of $50,000 or less per tax year, you can elect the small tax case procedure, known as an “S case.” S cases use simplified rules of evidence and procedure, which makes them workable if you represent yourself.12Office of the Law Revision Counsel. 26 U.S. Code 7463 – Disputes Involving $50,000 or Less The trade-off: an S case decision is final. Neither side can appeal to a higher court, and it cannot be used as precedent.
Costs and Risks Before You File
Interest Keeps Running
Interest on unpaid tax continues to accrue throughout the appeal. The IRS does not generally pause or forgive interest while a case is pending — the charges accumulate until the tax, penalties, and interest are fully paid.13Internal Revenue Service. Topic No. 653, IRS Notices and Bills, Penalties and Interest Charges Lose the appeal and you owe more than the original bill. Weigh that against the potential savings.
The Frivolous Submission Penalty
An appeal based on a position the IRS has identified as frivolous — arguing that wages are not taxable income, for instance, or that filing a return is voluntary — triggers a $5,000 penalty per submission.14Office of the Law Revision Counsel. 26 USC 6702 – Frivolous Tax Submissions It applies on top of any other taxes or penalties. You can avoid the penalty by withdrawing the submission within 30 days after the IRS notifies you it qualifies as frivolous, but the safer approach is to build your appeal on a genuine factual or legal disagreement.
Filing Fees
An administrative appeal with the IRS itself costs nothing. Form 12203 and formal written protests are free. Petitioning Tax Court costs $60. Local property tax fees range from nothing to over $100 depending on jurisdiction. The larger expense is usually the supporting evidence: appraisals, accountant fees for reconstructing records, or attorney representation in a complex case.
Getting Help
You are not required to handle a tax appeal alone. Attorneys, certified public accountants, and enrolled agents are all authorized to represent you before the IRS. Enrolled retirement plan agents and enrolled actuaries can represent you on certain specialized matters. In limited circumstances, an unenrolled preparer who signed your return may also represent you.15Internal Revenue Service. Power of Attorney and Other Authorizations
If you cannot afford representation, Low Income Taxpayer Clinics may help. These clinics represent eligible taxpayers before the IRS and in court at no charge or for a small fee. You can find one through the IRS website or by calling the Taxpayer Advocate Service.
For property tax appeals, some professionals work on a contingency basis, charging a percentage of the tax savings they achieve rather than an hourly rate. If you go that route, get the agreement in writing and confirm how the fee is calculated, including whether it applies to savings in future years.