A tax notice is a formal letter from a taxing authority, most often the IRS, telling you that something on your tax account needs attention. It might flag a balance you owe, correct an error on your return, question income you didn’t report, or ask for documents. Every notice carries a deadline, and every notice carries a notice number in the upper corner (something like CP14 or CP2000) that identifies exactly what the IRS is telling you. How you handle the first few weeks after opening the envelope usually decides whether the matter closes quickly or turns into a collection case.
Why the IRS Sent It
Notices aren’t random. A handful of triggers account for most of them.
You owe a balance. The CP14 is the standard balance-due notice for individuals and typically asks for payment within 21 days. It often shows up when withholding was too low or quarterly estimated payments were missed.1Office of the Law Revision Counsel. 26 U.S. Code 6654 – Failure by Individual to Pay Estimated Income Tax
The IRS fixed a math or clerical error. The notice shows the correction and the resulting balance or refund. You generally don’t need to amend your return, but check the math yourself. The IRS gets it wrong sometimes too.
Your income doesn’t match what third parties reported. This is the most common reason. The Automated Underreporter program compares your return against W-2s, 1099s, and similar forms, and mismatches produce a CP2000 proposing a higher tax bill. You have 30 days to respond, or 60 days if you live outside the United States.2Internal Revenue Service. Topic No. 652, Notice of Underreported Income – CP2000
Your return is being examined. The IRS may request documentation for a specific deduction, credit, or income item. Correspondence audits handled by mail are far more common than in-person examinations.
Your refund was reduced. The Treasury Offset Program can redirect a refund toward past-due child support, federal student loans, state income tax debts, or certain unemployment compensation debts.3Internal Revenue Service. Reduced Refund
Someone filed under your Social Security number. The IRS may send a notice about a return you didn’t file. Confirmed identity theft victims receive a CP01A each year containing an Identity Protection PIN to include on future returns.4Internal Revenue Service. Get an Identity Protection PIN
Is the Notice Real?
Tax scams look convincing. A few facts separate genuine IRS mail from fraud.
The IRS initiates contact by postal mail. It does not send emails, text messages, or social media messages asking for personal or financial information.5Internal Revenue Service. Get Your Tax Records and Transcripts Every legitimate notice carries a notice number in the upper corner.
There is one exception worth knowing. The IRS assigns certain overdue accounts to private collection agencies, and those agencies may call. Before any private collector contacts you, though, the IRS first mails a CP40 notice with a Taxpayer Authentication Number, and the collection agency then sends its own letter with the same number. If someone claims to be collecting for the IRS but you never got a CP40, treat it as fraud.6Internal Revenue Service. Private Debt Collection
To confirm a letter yourself, log into your IRS Online Account and view digital copies of notices the agency has sent you.7Internal Revenue Service. Online Account for Individuals You can also pull a tax transcript, available online instantly or by mail in 5 to 10 days, to see whether the balance or adjustment shows on your account.5Internal Revenue Service. Get Your Tax Records and Transcripts If something still feels off, call using the number on the notice or the main number at irs.gov, not a number printed in a suspicious letter.
What to Do First
Read the whole notice before doing anything else. Find three things: the tax year at issue, the exact dollar amount, and the response deadline. Those deadlines are not suggestions. Miss one and the IRS can assess the proposed liability automatically and begin collection.
Then gather documents. If the notice questions a deduction, pull the receipts. If it flags unreported income, collect the W-2s, 1099s, and brokerage statements from that year and compare them line by line with what you reported. The discrepancy often traces to a form you forgot about, like a 1099-INT from a small bank account.
Now decide. If the notice is right and you owe, paying quickly stops penalties and interest from growing. If it’s wrong, your documentation is your response.
How to Respond
By Mail
Send your response by certified mail with return receipt requested. That receipt is your proof of timely delivery if the IRS later says nothing arrived. Include the notice number, tax year, and your Social Security number or EIN. State briefly why you disagree and attach copies of supporting documents. Never send originals. A short cover page listing each enclosure helps the examiner and helps your case.
Online
The IRS Document Upload Tool accepts scanned documents, photos, and PDFs for many notice types. You’ll need either the access code printed on your notice or the notice number itself, along with your name and taxpayer identification number. Select the correct notice type from the dropdown; the wrong choice can delay processing.8Internal Revenue Service. IRS Document Upload Tool You cannot file returns through this tool.
If You Agree and Want to Pay
IRS Direct Pay moves funds from a bank account for free, with no registration required.9Internal Revenue Service. Direct Pay with Bank Account You can select the specific notice number as the reason for payment so the IRS applies it correctly.10Internal Revenue Service. Types of Payments Available to Individuals Through Direct Pay Checks and money orders work, and any payment voucher that came with the notice should go in the envelope. Credit and debit cards are accepted but carry a processor fee.
The 90-Day Letter
A Statutory Notice of Deficiency, often called a 90-day letter or notice CP3219N, is a hard deadline. You have exactly 90 days from the date on the notice to petition the U.S. Tax Court, or 150 days if you’re outside the country. Filing a late return does not extend this window. If the amount in dispute is $50,000 or less per year, the Tax Court offers simplified small-case procedures.11Internal Revenue Service. Understanding Your CP3219N Notice Miss the 90 days and you lose the right to challenge the assessment in Tax Court before paying.
Administrative Appeals
If you disagree with a final determination, you can request review by the IRS Independent Office of Appeals, an internal but independent body designed to resolve disputes without litigation.12Internal Revenue Service. Appeals
What Delay Costs
Two charges run at the same time on an overdue account. The failure-to-file penalty is 5% of the unpaid tax for each month or partial month a return is late, capped at 25%. The failure-to-pay penalty is 0.5% per month on the unpaid balance, also capped at 25%.13Office of the Law Revision Counsel. 26 USC 6651 – Failure to File Tax Return or to Pay Tax When both apply in the same month, the failure-to-file penalty is reduced by the failure-to-pay amount, so the combined rate runs at 5% per month for the first five months.14Internal Revenue Service. Failure to File Penalty If you can’t pay, file anyway. Filing on time eliminates the larger penalty.
Interest is separate. It runs from the original due date until the balance is paid, at a rate the IRS sets quarterly. For the first quarter of 2026, the individual underpayment rate is 7% per year, compounded daily.15Internal Revenue Service. Interest Rates Remain the Same for the First Quarter of 2026 On a $10,000 balance, that’s roughly $700 a year in interest alone, before penalties.
Getting Penalties Reduced
Penalties aren’t necessarily permanent. Under first-time abatement, if you have a clean penalty record for the three tax years before the year in question and have filed all required returns (or valid extensions), the IRS can waive failure-to-file, failure-to-pay, and failure-to-deposit penalties. Starting with the 2026 filing season, the IRS applies this relief automatically for eligible taxpayers on returns for tax years beginning in 2025 and later. If the automatic abatement doesn’t post to your account, you can request it by phone or mail.
If you don’t qualify for first-time abatement, you can request penalty relief for reasonable cause by showing you exercised ordinary care but couldn’t comply on time because of circumstances beyond your control. The IRS recognizes fires, natural disasters, serious illness or death in the immediate family, and system outages that blocked timely electronic filing. Not knowing the rules, blaming a preparer without more, or simply lacking the money generally don’t work. Even when a penalty is removed, interest on the underlying tax keeps accruing; the IRS has very limited authority to waive interest.16Internal Revenue Service. Penalty Relief for Reasonable Cause
If You Can’t Pay in Full
Owing money you can’t pay right now is not the same as having no options. Ignoring the bill is the worst move, because it drives the account into active collection. Three programs keep the IRS at the table.
Installment agreements. The IRS offers monthly payment plans. Applying online carries lower setup fees than phone or mail. Short-term plans of 120 days or fewer have no setup fee. Interest and the reduced failure-to-pay penalty keep running during the plan, but active collection stops.
Offer in compromise. An OIC settles the debt for less than the full amount when the IRS agrees you can’t pay it all. You must have filed all required returns, made required estimated payments, not be in an open bankruptcy, and (for employers) be current on payroll deposits. The application fee is $205, waived for low-income taxpayers, and you must submit a proposed payment with the application.17Internal Revenue Service. Offer in Compromise The IRS accepts a small fraction of offers it receives, so this works best when the numbers genuinely show you can’t pay.
Currently not collectible status. If paying anything would leave you unable to cover basic living expenses, you can ask the IRS to place your account in CNC status, usually by documenting your finances on Form 433-A. Active collection is suspended, but penalties and interest continue to accumulate.18Internal Revenue Service. 5.16.1 Currently Not Collectible It’s a pause, not a resolution, but it prevents levies and gives you room to plan.
What Happens If You Ignore It
Ignoring a notice sets off an escalating collection process, and every step gives the IRS more power over your finances. The agency starts with letters demanding payment in full. If nothing happens, it may file a Notice of Federal Tax Lien, a public record that attaches to your property (including property you acquire later), damages your credit, and alerts other creditors that the government has a claim.19Internal Revenue Service. Topic No. 201, The Collection Process
If the debt still isn’t resolved, the IRS can issue a levy. Levies actually seize assets: wages, bank accounts, Social Security benefits, retirement income, vehicles, real estate. The IRS can also intercept future federal and state tax refunds.19Internal Revenue Service. Topic No. 201, The Collection Process By the time a case reaches levy, you’ve received several notices and had multiple chances to resolve it. The IRS doesn’t skip steps. It also doesn’t stop.
When to Get Help
You have the right to be represented before the IRS. Once a notice moves past a simple balance-due situation, especially into an audit or a proposed deficiency, professional help can change the outcome. Attorneys, CPAs, and enrolled agents can represent you using Form 2848, Power of Attorney. An unenrolled preparer who signed your return has limited authority to represent you on matters tied to that return.20Internal Revenue Service. Form 2848, Power of Attorney and Declaration of Representative
If you can’t afford representation, Low Income Taxpayer Clinics offer free or low-cost help. And if you’re facing economic hardship, significant costs, or have gone more than 30 days without resolution through normal channels, the Taxpayer Advocate Service can step in on your behalf. TAS is an independent organization inside the IRS, and its assistance is free.21Internal Revenue Service. Who May Use the Taxpayer Advocate Service?