A letter arrives from the IRS saying you owe more than you thought you did, and the number at the bottom doesn’t match anything you remember signing. That’s a proposed tax assessment, and it isn’t final yet. It becomes final only if you let the clock run out without responding.
You can challenge it. The IRS built an appeals process specifically for taxpayers who disagree with an examiner’s findings, and in most cases you never have to set foot in a courtroom to use it.
Evan L. Smith, Attorney at Law has spent decades reading financial records the way an accountant does, then arguing them the way a litigator does. If a notice showed up in your mailbox this week, that combination is exactly what the next 30 days call for.
What a Proposed Assessment Really Means
A proposed assessment is the IRS telling you what it thinks you owe, not what you owe. Nothing is collected, no lien is filed, and no balance shows up on your account until the proposed amount becomes final, either because you agree to it or because the response window closes without you.
The notice usually follows an audit, a mismatch between your return and a third-party document like a 1099, or a deduction the examiner disallowed. Whatever triggered it, the document itself is an invitation to respond.
The 30-Day Letter Is Your Real Deadline
The 30-day letter, sometimes called Letter 525, is the document that starts your clock. It arrives after an audit closes without agreement, and it gives you 30 days from its date to ask the Independent Office of Appeals to look at the case fresh, separate from the examiner who wrote the report.
Small Case Request or Formal Protest
If the proposed change is under $25,000 for the tax year, an informal letter explaining what you disagree with and why is usually enough. Above that threshold, the IRS wants a formal written protest that includes your contact information, the tax years in question, a clear statement of each disputed item, and the facts and law supporting your position, all submitted under penalty of perjury.
Why the Accounting Behind the Numbers Matters
Most protests fail on the numbers, not the law. An examiner disallows a deduction because the paper trail looks thin, and the taxpayer argues policy instead of producing the missing invoice. Attorneys who came up reading balance sheets before they ever read the tax code tend to catch that gap first, because they were trained to ask for the receipt before they ask for the ruling.
Building a Protest the Office of Appeals Will Take Seriously
A protest that moves your case forward covers three things:
- A clear statement identifying the tax years and dollar amounts you’re disputing, item by item, not just a general objection to the outcome.
- A statement of facts, signed under penalty of perjury, that lays out what happened without embellishment. Appeals officers weigh hazards of litigation, meaning what the IRS would risk losing at trial, and an exaggerated fact pattern loses credibility fast.
- The law or IRS guidance that supports your position, tied directly to the disputed facts rather than dropped in as a general citation.
Send it by certified mail to the address on your 30-day letter, and keep the receipt.
Missing the Window: The Notice of Deficiency and Tax Court
Ignore the 30-day letter, or lose at Appeals, and the next document you get is a Notice of Deficiency. It comes by certified mail, and unlike the letter before it, there’s only one way to respond: petitioning the United States Tax Court before the deadline printed on page one of the notice runs out. You generally have 90 days from the mailing date — or 150 days if the notice was mailed to you at an address outside the United States.
What the Notice of Deficiency buys you, and it’s a real benefit, is time without payment. File the Tax Court petition and the IRS cannot assess or collect the proposed amount while the case is pending, so you get your day in court before a dollar changes hands. Skip the petition and the assessment simply becomes final, collection notices start, and a federal tax lien becomes a real possibility rather than a hypothetical one.
California Runs Its Own Clock: FTB Notices of Proposed Assessment
A California return under audit follows a separate, parallel process through the Franchise Tax Board, and the deadlines don’t match the federal ones. The FTB issues its own Notice of Proposed Assessment, and California Revenue and Taxation Code Section 19041 gives you 60 days from that notice, not 30, to file a written protest before the amount becomes final.
Pay the proposed balance within 15 days of the notice and the FTB stops charging interest on it while your protest is pending. If the FTB affirms the assessment after your protest, it issues a Notice of Action, and you get 30 days from that document to appeal to the independent Office of Tax Appeals, a body separate from the FTB that can hold a hearing or decide the case on the papers.
Residents working through a Temecula Valley or wider Riverside County audit often assume the state will simply mirror whatever the IRS decided, and sometimes it does, but the two clocks run independently and missing one doesn’t extend the other. A tax attorney who handles both the federal and state side can keep the two deadlines straight without missing either one.
FAQs About Challenging a Proposed Tax Assessment
Do I have to pay the proposed tax before I can dispute it?
No, not if you act during the window that keeps the case administrative or judicial rather than collection. Petitioning the U.S. Tax Court after a Notice of Deficiency lets you dispute the full amount before paying a dollar of it. Miss that window and most other options require paying first, then filing a refund claim.
What if I already missed the 30-day protest deadline?
You’re not automatically out of options, but your position weakens fast. Once the Notice of Deficiency arrives, you’ll get 90 days to petition the Tax Court instead of the earlier informal path through Appeals. After that, the assessment can become final and collection activity, including liens, can start.
Can I dispute a penalty separately from the underlying tax?
Yes, penalties are frequently challenged on their own even when the tax itself isn’t in dispute. Showing reasonable cause, such as relying on a professional preparer or a documented medical emergency, can remove penalties the IRS added for late filing or accuracy. Some penalties also qualify for first-time abatement regardless of the reason behind them.
Does the IRS Office of Appeals really settle most cases?
Yes, the large majority of protests that reach Appeals resolve there without ever going to trial. Appeals officers weigh the hazards of litigation, meaning what the government risks losing in court, rather than simply re-running the examiner’s numbers. A well-documented protest gives them something concrete to settle around.
How is a California FTB dispute different from an IRS one?
The two run on separate timelines, through separate agencies, so a win or loss with one doesn’t automatically decide the other. An FTB Notice of Proposed Assessment gives you 60 days to protest, compared to the IRS’s 30-day window. If the FTB doesn’t budge, the next stop is the independent Office of Tax Appeals rather than U.S. Tax Court.
Evan L. Smith, Attorney at Law: Your Temecula Valley Tax Law Firm
A notice proposing more tax doesn’t mean the number on it is right, and it doesn’t mean you’re out of options. It means the clock started, and how you spend the next 30 or 60 days decides whether this gets resolved at Appeals or drags into Tax Court.
Evan L. Smith has spent decades reading the financial detail an examiner’s report leaves out, the kind of gap that decides whether a protest holds up. Contact our firm today.
