That IRS Letter Is More Urgent Than It Looks.

Opening a letter from the IRS and seeing a Notice of Deficiency — sometimes called a 90-day letter — can be alarming. The notice states that the IRS has determined you owe additional taxes, and it looks like an ordinary bill. But it is far more than that. A Notice of Deficiency is a formal legal document that triggers one of the most important deadlines in tax law: you have exactly 90 days to respond, or you lose the right to challenge the IRS's determination in court before paying the disputed amount.

At Bender Law, we help individuals and businesses in Watertown and throughout Wisconsin understand what a Notice of Deficiency means, evaluate their options, and take swift, effective action. If you have received this notice, time is not on your side — but the right attorney can make all the difference.

What Is a Notice of Deficiency?

A Notice of Deficiency — formally issued as IRS Notice CP3219A or IRS Letter 531 — is the IRS's official determination that you owe more tax than you reported on your return. It is issued after the IRS has audited your return or identified a discrepancy through its automated systems, and either no agreement was reached or no response was received.

The notice is sometimes called a "90-day letter" because it gives the taxpayer 90 days from the date of the notice to file a petition with the U.S. Tax Court challenging the IRS's determination. (Taxpayers residing outside the United States have 150 days.) This is a critical legal right — and one that expires absolutely if not exercised in time.

The Notice of Deficiency typically includes:

• The tax year or years at issue
• The amount of additional tax the IRS claims is owed
• A breakdown of the proposed adjustments to your return
• The deadline by which you must file a Tax Court petition to contest the determination
• Form 5564 (Notice of Deficiency Waiver), which you sign if you agree with the assessment

Despite its legal significance, the notice is often formatted to look like a standard IRS billing letter — which leads many taxpayers to underestimate its importance or miss the deadline entirely. Do not let that happen.

Why Does the IRS Issue a Notice of Deficiency?

The IRS issues a Notice of Deficiency when it believes additional tax is owed and the normal resolution process has not produced an agreement. Common reasons include:

• Underreported income — The IRS received information from employers, banks, investment firms, or other third parties that does not match the income you reported on your return.
• Disallowed deductions or credits — The IRS has determined that deductions or credits you claimed — such as business expenses, charitable contributions, or the Earned Income Tax Credit — are invalid, unsupported, or exceed allowable limits.
• No return filed — The IRS prepared a substitute return on your behalf based on third-party information, resulting in a proposed assessment.
• Failed audit — An IRS audit concluded with proposed adjustments that you either disagreed with at the audit level or did not respond to.
• Unresolved IRS Appeals — You appealed an audit finding to the IRS Office of Appeals, but the dispute was not resolved, triggering the formal deficiency process.
• Math errors or computational discrepancies — The IRS identified errors in the calculations on your return that result in a higher tax liability than reported.

Your Options When You Receive a Notice of Deficiency

Upon receiving a Notice of Deficiency, you have three primary options. Understanding which is right for your situation — and acting before the deadline — is critical.

Option 1: Agree with the IRS Assessment

If you review the notice and believe the IRS's determination is correct, you can sign and return Form 5564 (the waiver) and arrange to pay the amount owed. You can pay in full or request an installment agreement. Agreeing with the assessment ends the dispute but does not eliminate any penalties and interest that have accrued. Even if you agree with the underlying tax, it may be worth consulting an attorney about penalty abatement options before signing.

Option 2: Petition the U.S. Tax Court

If you believe the IRS's determination is incorrect — in whole or in part — you can file a petition with the U.S. Tax Court within 90 days of the date on the notice. This is the most powerful option available to you because it allows you to challenge the IRS's assessment before paying any of the disputed amount. The Tax Court is an independent federal court that hears tax disputes, and its judges are specialists in tax law.

Filing a Tax Court petition does not mean your case will go to trial. The majority of Tax Court cases are resolved through negotiation and settlement before trial, often resulting in a reduced assessment. However, the petition must be filed correctly and on time — a defective or late petition can be dismissed, leaving you without recourse.

If the disputed amount is $50,000 or less per tax year, you may qualify for the Tax Court's Small Tax Case ("S case") procedure — a simplified, less formal process designed to be more accessible to taxpayers. We can evaluate whether this option is appropriate for your situation.

Option 3: Pay and Seek a Refund

If the 90-day deadline has passed without a Tax Court petition being filed, the assessment becomes final and the IRS begins collection. At that point, your remaining option to challenge the underlying tax is to pay the full amount and file a formal claim for a refund. If the IRS denies the refund claim, you can pursue the dispute in U.S. District Court or the Court of Federal Claims — but you must pay first. This is a significantly more burdensome path than petitioning the Tax Court during the 90-day window.

Understanding the 90-Day Deadline

The 90-day deadline is one of the most absolute deadlines in all of federal law. There are no extensions, no exceptions for postal delays, and no grace periods. The clock starts on the date printed on the notice — not the date you received it — which means every day matters from the moment the IRS mails the letter.

Critical Deadline Facts

The 90-day period begins on the date printed on the Notice of Deficiency — not the date you receive it.

Sending a letter or calling the IRS does NOT stop the clock. Only filing a proper Tax Court petition suspends collection and preserves your rights.

If the 90-day deadline passes without a petition, the assessment becomes final, the IRS can begin collection actions (wage garnishment, bank levies, property liens), and your right to challenge the tax before paying is lost.

Taxpayers residing outside the United States have 150 days instead of 90 days.

If the last day falls on a Saturday, Sunday, or legal holiday, the deadline extends to the next business day.

Responding in U.S. Tax Court: What to Expect

Filing a petition with the U.S. Tax Court initiates a formal legal proceeding. Here is what the process generally looks like:

1. Filing the Petition — The petition is a formal document that identifies the taxpayer, attaches a copy of the Notice of Deficiency, states the tax years and amounts in dispute, and briefly describes the basis for the challenge. It must be filed with the U.S. Tax Court in Washington, D.C. within the 90-day window — either electronically or by mail with proper proof of timely filing.
2. IRS Answer — After the petition is filed, the IRS (represented by IRS Chief Counsel attorneys) files a formal answer responding to the taxpayer's claims.
3. Discovery and Case Development — Both sides gather evidence, exchange documents, and develop their legal and factual arguments. This is the phase where having experienced legal representation is most valuable — the IRS attorneys are professionals; you should be too.
4. Settlement Negotiations — The vast majority of Tax Court cases settle before trial. The IRS Office of Appeals and IRS Chief Counsel often engage in active settlement discussions. A negotiated resolution can result in a reduced assessment, adjusted penalties, or other favorable terms.
5. Trial (If Necessary) — If a settlement cannot be reached, the case proceeds to trial before a Tax Court judge. The Tax Court holds trial sessions in cities across the country — for Wisconsin taxpayers, cases are typically heard in Milwaukee. You bear the burden of proving that the IRS's determination is incorrect.
6. Decision and Appeal — The Tax Court issues a written decision. Either party may appeal to the appropriate U.S. Court of Appeals — for Wisconsin taxpayers, that is the Seventh Circuit.

Wisconsin Taxpayers: State-Level Considerations

A federal Notice of Deficiency addresses only your federal tax liability with the IRS. However, an IRS audit finding or deficiency determination often has consequences at the state level as well.

Wisconsin Department of Revenue — Conformity

Wisconsin generally conforms to federal tax law in many areas, and the Wisconsin Department of Revenue (DOR) typically receives notification of federal audit adjustments. If the IRS determines that you owe additional federal income tax, the Wisconsin DOR may initiate its own review and issue a corresponding state tax assessment. Managing both the federal and state implications of a deficiency notice — simultaneously and strategically — requires careful coordination.

Wisconsin DOR Notices of Additional Tax

The Wisconsin DOR also issues its own deficiency-style notices when it believes additional state income tax is owed. These notices are governed by Wisconsin Statutes Chapter 71 and carry their own deadlines and appeal rights through the Wisconsin Tax Appeals Commission. If you have received a notice from the Wisconsin DOR in addition to or instead of an IRS Notice of Deficiency, our attorneys can advise you on both.

Intersection with Other Legal Matters

Tax deficiency issues do not always arise in isolation. They can intersect with business disputes, estate administration, divorce proceedings, and real estate transactions. As a full-service general practice firm serving Watertown and Jefferson County, Bender Law understands how a tax dispute can affect other areas of your legal and financial life — and we can coordinate representation across those areas when needed.

Who We Represent

Our IRS tax controversy practice serves individuals and small businesses throughout Watertown and southeastern Wisconsin, including:

• Individuals who have received an IRS Notice of Deficiency and need to understand their options
• Taxpayers who disagree with IRS audit findings and want to challenge the determination
• Individuals facing a proposed tax assessment based on unreported or misreported income
• Taxpayers whose deductions, credits, or business expenses were disallowed by the IRS
• Small business owners facing employment tax, self-employment tax, or business expense disputes
• Taxpayers who have already missed the 90-day deadline and need to explore post-assessment options
• Individuals facing both federal IRS and Wisconsin DOR deficiency proceedings simultaneously
• Taxpayers who have received a Wisconsin DOR notice of additional tax due

How We Can Help

Bender Law provides comprehensive representation for Wisconsin taxpayers navigating a Notice of Deficiency and related IRS tax controversy matters. Our services include:

• Reviewing your Notice of Deficiency and the IRS's proposed adjustments
• Evaluating the merits of the IRS's position and advising on the strength of a challenge
• Preparing and filing a petition with the U.S. Tax Court within the 90-day deadline
• Representing you in Tax Court proceedings, including discovery, negotiations, and trial if necessary
• Negotiating with IRS Office of Appeals and IRS Chief Counsel to pursue a favorable settlement
• Pursuing penalty abatement to reduce interest and penalties even when underlying tax is agreed upon
• Advising on post-assessment options if the 90-day deadline has passed
• Addressing corresponding Wisconsin DOR notices and state-level tax controversy matters
• Coordinating tax dispute resolution with related business, estate, or family law matters

Why Clients Choose Bender Law

Urgent, Experienced Response — We understand that a Notice of Deficiency is time-sensitive. We move quickly to review your situation, advise you on your options, and take action before critical deadlines pass.

Honest Assessment — We will tell you clearly whether the IRS's position appears correct, where the weaknesses in your case are, and what a realistic outcome looks like. You will never be misled about your chances.

Local Knowledge, Broad Expertise — As a full-service firm rooted in Watertown and Jefferson County, we understand how a federal tax dispute can affect your broader legal and financial situation — and we bring the full depth of our practice to every client.

Clear Communication — Tax law is complex. We explain it in plain language, keep you informed at every step, and make sure you understand every decision and every option.

Frequently Asked Questions

I just received a Notice of Deficiency. What should I do first?

The most important first step is to note the date printed on the notice and calculate your 90-day deadline. Do not ignore the notice, and do not assume you can call the IRS and resolve it informally — phone calls and letters do not stop the 90-day clock. Contact an attorney as soon as possible. The earlier you engage legal counsel, the more time there is to evaluate your options, gather documentation, and file a proper Tax Court petition if that is the right path.

What if I agree with part of the IRS's assessment but not all of it?

You can file a Tax Court petition that disputes only the portions of the assessment you believe are incorrect — you do not have to challenge the entire deficiency. In fact, conceding undisputed items early in the process often strengthens your position on the items you do dispute and can accelerate resolution. Our attorneys can help you identify exactly which adjustments are worth challenging and how to frame your case most effectively.

Can I still negotiate with the IRS after filing a Tax Court petition?

Yes — and in fact, most Tax Court cases are resolved through negotiation before they ever reach trial. Filing a petition does not end settlement discussions; it preserves your rights while those discussions continue. Once a petition is filed, your case is assigned to IRS Chief Counsel, and the IRS Office of Appeals may also remain involved. Reaching a negotiated resolution is often the most efficient and cost-effective outcome for all parties.

What if I missed the 90-day deadline?

If the 90-day period has passed without a Tax Court petition being filed, the IRS will assess the deficiency and begin collection. Your right to challenge the assessment in Tax Court before paying is lost. However, options remain. You may be able to request audit reconsideration if you have new information the IRS did not consider. You may also be able to pay the tax and file a claim for a refund, then pursue the dispute in U.S. District Court or the Court of Federal Claims. An Offer in Compromise based on Doubt as to Liability may also be an option in some cases. We can evaluate what relief may still be available.

What is a Small Tax Case, and do I qualify?

If the disputed tax amount is $50,000 or less per tax year, you may elect to have your Tax Court case handled under the Small Tax Case ("S case") procedure. This is a simplified, less formal process with shorter timelines and more relaxed evidentiary rules — designed to make Tax Court more accessible to taxpayers without attorneys. However, Small Tax Case decisions cannot be appealed. Our attorneys can help you weigh the trade-offs and determine which procedure best fits your situation.

Does receiving a Notice of Deficiency mean I will definitely owe more taxes?

Not necessarily. A Notice of Deficiency represents the IRS's proposed assessment — it is not a final determination. Many taxpayers who challenge a Notice of Deficiency in Tax Court succeed in reducing or eliminating the proposed assessment entirely. The outcome depends on the specific facts, the documentation you can present, and the legal arguments available. That is why an honest, early evaluation of your case by an experienced attorney is so important.

Serving Taxpayers Throughout Southeastern Wisconsin

Bender Law is based in Watertown, Wisconsin, and serves individuals and small businesses across Jefferson County, Dodge County, and the surrounding region. We assist clients with IRS tax controversy matters in Watertown, Jefferson, Juneau, Whitewater, Lake Geneva, Elkhorn, Johnson Creek, Oconomowoc, Delavan, Janesville, and beyond. As a full-service general practice firm with decades of experience serving Wisconsin families and businesses, we bring broad legal knowledge and genuine personal attention to every client we represent.

Received an IRS Notice of Deficiency? Contact Bender Law Today.

The 90-day deadline moves fast. If you have received a Notice of Deficiency, do not wait to speak with an attorney. Contact Bender Law today to schedule a consultation and protect your rights before the clock runs out.

(920) 261-7626  |  138 Hospital Dr., Suite 100, Watertown, WI 53098