Finding an envelope from the IRS in your mailbox can stop you in your tracks. But before you panic, it helps to know that many IRS notices are routine, and the notice number in the upper-right corner tells you exactly what it means. Whether you’re staring at CP14, CP2000, CP12, CP49, Notice 504, or something else, a little context goes a long way toward helping you decide your next move. Below, we explore five common IRS notices and break down what they mean.
At a glance:
You can view some IRS notices and letters in your IRS online account after you verify your identity.
Common IRS notices include CP14 (balance due), CP2000 (proposed changes to tax return), CP12 (refund adjustment), CP49 (the IRS used your refund to pay a debt), and more.
Respond by the deadline on your notice, and consider contacting a tax professional if you disagree with the notice or cannot pay a balance due in full.
Can you view IRS notices online?
Yes, the IRS website lets eligible taxpayers access tax account information through their IRS online account. After you verify your identity, you can review payment history, see whether you have taxes owed, and, in many cases, view digital copies of IRS notices and letters.
Paperless notices are not available for every letter type, so it’s still best to keep any paper mail you receive from the IRS. Your online account is a helpful supplement, not a complete replacement for physical IRS notices. If you do not see your notice online, search for the notice number on irs.gov or call the number printed on the letter.
Tax tip: If you want additional help decoding a specific IRS letter, TaxAct® has a guide to common IRS notices with links to sample copies and step-by-step guidance for many IRS letters and notices.
Common IRS notices explained
Not every IRS letter means you are in trouble, and many are routine adjustment notices or informational updates that don’t require a response.
Below, we cover the notices most filers search for, including CP14, CP2000, CP12, CP49, and Notice 504. But first, here’s a helpful table to compare each notice side by side:
IRS notice CP14: balance due
IRS notice CP14 is one of the most common balance due letters. It means the IRS processed your tax return and you owe money, but the agency is not claiming a math error on the return itself.
Your CP14 shows:
Your tax liability
Any payments already applied toward your tax liability
The remaining balance due
What to do: The notice also lists a due date for payment, after which interest and penalties may begin to accrue. Even if you cannot pay the full amount, paying something by the due date can limit additional charges. You may also qualify for an online payment agreement or installment agreement through irs.gov.
If you believe the amount is wrong, gather your tax records and call the IRS at the number listed on your notice before the deadline. Have your paperwork handy when you call!
Tax tip: There are several ways to pay your balance due. Our guide to paying your income tax bill walks through payment options step by step.
IRS notice CP2000: underreported income
IRS notice CP2000 is not a bill. It is a proposed change to your federal tax return based on information the IRS received from employers, banks, or other payers that does not match what you reported.
The CP2000 includes a tax compliance report comparing your return to third-party data. Common triggers for this notice include:
Missing Form W-2
Unreported freelance income
Investment income that does not appear on your Form 1040
What to do: Read every line carefully before you agree or disagree. You typically have 30 days to respond, and you can do so by mail, fax, or the IRS document upload tool (the fastest way).
If you agree, follow the payment instructions (get help if you can’t pay in full). If you disagree, send documentation explaining why your original return was correct.
Ignoring a CP2000 can lead to a notice of deficiency and more serious collection steps. Learn more in our article on how to respond to IRS letters .
Tax tip: If you need a copy of a prior federal tax return, you can request transcripts using Form 4506-T through irs.gov. If you filed with TaxAct, sign in to access your current or prior-year returns.
IRS notice CP12: refund adjustment
IRS notice CP12 means the IRS corrected one or more mistakes on your tax return that resulted in a refund adjustment. This is one of several adjustment notices the IRS sends after processing. You may receive a larger or smaller refund than expected, or you may now be due a refund you did not expect at all.
What to do: Compare the corrected figures to your filed return. If the math checks out, you do not need to reply, but if something looks off, call the IRS at the number shown in the notice by the response deadline. If the IRS needs a missing or corrected document from you, you may be asked to fax the necessary information.
IRS notice CP49: overpayment applied to other debt
IRS notice CP49 tells you the IRS used your tax overpayment to pay other federal taxes or debts you owe, meaning all or part of your refund was applied to an outstanding debt. This is called a tax refund offset. The notice lists which debts were satisfied and any remaining balance.
What to do: CP49 is purely informational when the offset is correct. However, if you did not owe the debt shown, or if you filed jointly and only one spouse owed the debt, call the IRS at the number provided. You may have options to dispute the offset, like filing Form 8379.
Tax tip: Keep CP49 with your tax records for at least three years.
IRS notice 504: urgent balance due
IRS notice 504, also called CP504, is an urgent balance due letter. It arrives after earlier reminders went ignored or unpaid and warns that the IRS may take stronger collection action, including filing a federal tax lien.
What to do: Don’t ignore Notice 504. Pay the balance in full if you can. If you can’t pay, you may be eligible for a payment plan, an installment agreement, or an offer in compromise, depending on your eligibility.
If you disagree with the notice, call the IRS as soon as possible at the phone number on your notice.
Tax tip: Our articles on what happens if you cannot pay your taxes and IRS payment plans explain your options in more detail.
Get help responding to IRS notices
When it’s time to respond to a notice, our step-by-step guide to responding to IRS letters walks you through the process. For more complex disputes, it might be wise to consult a tax professional or authorize representation with a power of attorney using Form 2848 (or Form 8821 for tax information authorization).
Tax tip: If you filed with TaxAct and added Audit Defense provided by Tax Protection Plus* at checkout, you may already have help available. Our Audit Defense offering can provide professional assistance responding to IRS inquiries on your behalf.
FAQs
The bottom line
IRS notices are manageable once you know what they mean. Check the notice number on your letter, then follow the instructions and respond by the deadline if the IRS requests action.
For sample copies and guidance on other notice types, view our Audit Assistant IRS Notice Listing.
This article is for informational purposes only and not legal or financial advice.
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Citations
Internal Revenue Service. “Online Account for Individuals.” IRS, 8 June 2026.Internal Revenue Service. “Understanding Your IRS Notice or Letter.” IRS, 26 May 2026.Internal Revenue Service. “Understanding Your CP14 Notice.” IRS, 23 June 2026.Internal Revenue Service. “Understanding Your CP2000 Series Notice.” IRS, 16 May 2026.Internal Revenue Service. “Understanding Your CP12 Notice.” IRS, 4 Nov. 2025.Internal Revenue Service. “Understanding Your CP49 Notice.” IRS, 19 Feb. 2026.Internal Revenue Service. “Understanding Your CP504 Notice.” IRS, 16 Dec. 2025.Internal Revenue Service. “Preparing a Request for Appeals.” IRS, 4 Apr. 2026.Internal Revenue Service. “IRS Document Upload Tool.” IRS, 8 June 2026.Internal Revenue Service. “Get Help with Tax Debt.” IRS, 4 June 2026.Internal Revenue Service. “About Form 4506-T, Request for Transcript of Tax Return.” IRS, 24 Oct. 2025.U.S. Department of the Treasury. “Treasury Offset Program FAQs.” Bureau of the Fiscal Service.Internal Revenue Service. “About Form 8379, Injured Spouse Allocation.” IRS, 30 Mar. 2026.Internal Revenue Service. “Understanding a Federal Tax Lien.” IRS, 6 Feb. 2026.Internal Revenue Service. “Offer in Compromise.” IRS, 22 May 2025.

















