If you don’t respond to an IRS audit, the agency finishes it without you: it calculates what it believes you owe from the information it already has, formally assesses the tax, piles on penalties and interest, and eventually moves to collect by liens and levies against your wages, bank accounts, and property. Silence doesn’t stop the audit. It just removes your side of the story from it, and every deadline you miss narrows what you can do about the bill later.
How the IRS Escalates When You Stay Silent
The IRS works through a structured series of letters, each one more serious than the last. Early notices ask for records or your agreement to proposed changes, and typically give you 30 days to respond. Ignore those and follow-up letters arrive with the same request and a shorter fuse.
Each unanswered letter pushes you closer to a unilateral assessment: the IRS deciding your tax bill for you, using only what third parties like employers, banks, and brokerages reported. Deductions you could have substantiated but never did are simply gone. Business expenses you never documented don’t exist as far as the assessment is concerned.
The Notice of Deficiency Is Your Last Real Chance
After the preliminary notices run out, the IRS issues a Notice of Deficiency, sometimes called a 90-day letter. It may arrive as Letter 3219 or Notice CP3219N.1Internal Revenue Service. Understanding Your CP3219N Notice This letter tells you exactly what the IRS thinks you owe and gives you 90 days (150 if you’re outside the country) to petition the U.S. Tax Court.2Taxpayer Advocate Service. Letter 3219, Notice of Deficiency
Tax Court is the only forum where you can challenge the proposed assessment without paying first. Let the 90 days lapse and the IRS formally assesses the tax. After that, your options shrink to paying the full balance and suing for a refund, or asking for an audit reconsideration — both harder and slower than answering the notice on time.
One warning about that clock: the IRS only has to mail the Notice of Deficiency to your last known address by certified mail. If you’ve moved and never updated the IRS, you may never see the letter, but it’s still legally valid and the 90 days still run. File Form 8822 or keep filing returns from your current address so this notice actually reaches you.
What Gets Added to the Bill
Once the IRS assesses tax based on its own numbers, several penalties can stack on top, and interest runs underneath all of them from the original due date of the return.
Accuracy-Related Penalty
The most common audit penalty is 20% of the underpayment. It applies when the shortfall comes from negligence, disregard of the rules, or a substantial understatement of income tax. For individuals, “substantial” means the understatement exceeds the greater of 10% of the tax that should have been shown on the return, or $5,000.3Office of the Law Revision Counsel. 26 U.S. Code 6662 – Imposition of Accuracy-Related Penalty on Underpayments
Failure to File and Failure to Pay
If the audit involves a return you never filed, a separate failure-to-file penalty runs at 5% of the unpaid tax per month, capped at 25%. Failure-to-pay adds 0.5% per month, also capped at 25%. When both apply in the same month, the failure-to-file amount is reduced so the combined hit is 5%, not 5.5%.4Office of the Law Revision Counsel. 26 USC 6651 – Failure to File Tax Return or to Pay Tax
Civil Fraud
If the IRS decides the underpayment was due to intentional deception rather than carelessness, the penalty jumps to 75% of the portion attributable to fraud.5Office of the Law Revision Counsel. 26 USC 6663 – Imposition of Fraud Penalty The IRS carries the burden of proving fraud by clear and convincing evidence, and it can’t stack fraud on top of the accuracy penalty for the same underpayment. Ignoring audit inquiries doesn’t help your defense.
Interest
Interest accrues daily on both the unpaid tax and the penalties, starting from the original due date of the return. For individuals, the rate is the federal short-term rate plus three points, adjusted quarterly; in the first quarter of 2026, that’s 7%.6Internal Revenue Service. Interest Rates Remain the Same for the First Quarter of 2026 Penalties are capped. Interest isn’t. It compounds until you pay.
Collection: Liens and Levies
After the assessment becomes final and the balance stays unpaid, the IRS moves into collection. Before it seizes anything, it must send a Final Notice of Intent to Levy, usually Letter 1058 or Notice LT11.7Internal Revenue Service. Understanding Your LT11 Notice or Letter 1058 You get 30 days to respond before the IRS can act.8Office of the Law Revision Counsel. 26 U.S. Code 6331 – Levy and Distraint
Federal Tax Liens
A federal tax lien is a legal claim against everything you own, including property you acquire after it attaches. It arises automatically once the IRS demands payment and you don’t pay.9Office of the Law Revision Counsel. 26 U.S. Code 6321 – Lien for Taxes When the IRS records a Notice of Federal Tax Lien in the public record, creditors learn the government has first priority on your assets. Selling a house, refinancing a mortgage, or getting a loan becomes very difficult.
Levies
A levy is the actual seizure. The IRS can garnish wages, drain bank accounts, intercept future tax refunds, and take physical property like vehicles and real estate.8Office of the Law Revision Counsel. 26 U.S. Code 6331 – Levy and Distraint Wage levies are continuous, taking a portion of every paycheck until the debt clears. Bank levies are a one-time freeze: your bank holds the funds for 21 days, then sends them to the IRS.
The Collection Due Process Hearing
The Final Notice of Intent to Levy carries a right most people don’t know they have. Within 30 days, you can file Form 12153 to request a Collection Due Process hearing.10Internal Revenue Service. Form 12153, Request for a Collection Due Process or Equivalent Hearing A timely CDP request pauses levy actions during the hearing and suspends the 10-year collection clock. If you disagree with the outcome, you can appeal to Tax Court. Miss the deadline and you can still ask for an “equivalent hearing,” but it won’t stop the levy and you lose the right to court review.
Your Passport Can Be Revoked
If your total unpaid federal tax debt, including penalties and interest, exceeds $66,000 in 2026, the IRS can certify it as “seriously delinquent” and notify the State Department.11Internal Revenue Service. Revenue Procedure 2025-32 The State Department can then deny a new passport application, refuse a renewal, or revoke a passport you already hold. You’ll get a CP508C notice when the certification is made.12Internal Revenue Service. Understanding Your CP508C Notice
The threshold adjusts for inflation each year. Certification only happens after the IRS has filed a tax lien and your administrative remedies have run out. If you’re a citizen abroad when your passport is revoked, the State Department may issue a limited-validity passport to let you return home. The IRS reverses the certification within 30 days once the debt is resolved through payment, an installment agreement, an offer in compromise, or a hardship determination.
When Ignoring the Audit Becomes Criminal
Most people who ignore audits face civil penalties, not criminal charges. But if the IRS concludes you willfully evaded tax, meaning you knew you owed and deliberately tried to avoid paying, the exposure changes character. Tax evasion is a felony carrying up to $100,000 in fines and five years in prison.13Office of the Law Revision Counsel. 26 USC 7201 – Attempt to Evade or Defeat Tax Willful failure to file a return is a misdemeanor carrying up to $25,000 in fines and one year in prison.14Office of the Law Revision Counsel. 26 USC 7203 – Willful Failure to File Return, Supply Information, or Pay Tax
Prosecutions are rare — the IRS refers only a few thousand cases a year, and simply not answering audit letters usually isn’t enough on its own. Patterns of hiding income, destroying records, or filing false returns raise the risk. Silence also makes it harder later to argue that any errors were honest mistakes.
How Long the IRS Can Come After You
Two clocks matter, and both cut against people who never respond. The IRS generally has three years from when a return is filed to assess additional tax. If you never filed at all, there is no statute of limitations. The IRS can assess whenever it wants.15Office of the Law Revision Counsel. 26 USC 6501 – Limitations on Assessment and Collection Fraudulent returns have no time limit either.
Once tax is assessed, the IRS has 10 years to collect it.16Office of the Law Revision Counsel. 26 USC 6502 – Collection After Assessment That clock pauses in several situations, including a pending CDP hearing, bankruptcy, a pending offer in compromise, or extended periods living outside the country. Waiting out the 10 years is not a plan.
What You Can Still Do After You’ve Missed the Deadlines
Even if you’ve ignored every notice and the tax is already assessed, you have paths forward. None are as effective as responding to the audit on time, but they can shrink the bill or make it manageable.
Audit Reconsideration
If you never participated in the audit or never turned over your records, you can ask for an audit reconsideration. No special form is required. Write to the IRS office that last contacted you, say what you disagree with, and attach copies of supporting documents.17Taxpayer Advocate Service. Audit Reconsiderations It’s available when you have new information, disagree with the assessed amount, or simply never showed up the first time.
You can’t request reconsideration if you signed a closing agreement, already accepted an offer in compromise on the same liability, or a court has issued a final decision on the tax. If you already paid the full balance, use an amended return (Form 1040-X) instead.
Payment Plans
Short-term plans give you up to 180 days to pay with no setup fee. Long-term installment agreements stretch payments over months or years, with setup fees running from $22 to $178 depending on how you apply and whether you agree to automatic debits.18Internal Revenue Service. Payment Plans; Installment Agreements Low-income taxpayers can have the setup fee waived. Penalties and interest keep running while you’re on the plan, but you avoid levies.
Offer in Compromise
An offer in compromise settles the debt for less than the full amount. The IRS approves these when the offered amount is the most it could reasonably expect to collect. Submit Form 656 with a detailed financial statement, a $205 application fee, and an initial payment (typically 20% of the offer for a lump-sum proposal).19Internal Revenue Service. Offer in Compromise You must be current on all required filings and estimated payments. Low-income applicants skip the fee and initial payment.
Currently Not Collectible Status
If paying would create real financial hardship, you can ask the IRS to place your account in currently not collectible status. Expect to submit detailed financial documentation. While in this status, the IRS won’t actively collect, though it will still apply future refunds to the balance and interest and penalties keep running. If you owe more than $10,000, the IRS usually files a federal tax lien as a condition.
Innocent Spouse Relief
If the assessment stems from income, deductions, or credits attributable to your spouse or former spouse on a joint return, file Form 8857 to ask the IRS to hold only the responsible spouse liable for that portion. The deadline is generally two years after the IRS first tries to collect from you, though different rules govern equitable relief. You’re ineligible if a court has ruled on the liability or you signed a closing agreement covering the same debt.20Internal Revenue Service. Instructions for Form 8857 – Request for Innocent Spouse Relief