IRS notice library
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Find your notice code below to learn exactly what it means, why you received it, and what you need to do next.
Critical Notices
These require immediate action. The IRS is about to take collection action.
CP504
Notice of Intent to Levy (IRC §6331(d))
The IRS notice that says it intends to levy — it does not carry a Collection Due Process hearing right
CP90
Final Notice of Intent to Levy
Last warning - levy action imminent
CP91
Final notice before levy on Social Security benefits
The IRS states it intends to levy up to 15% of your Social Security benefits for unpaid taxes.
CP297
Final Notice - Businesses - Intent to Levy
Final levy notice for business tax debt
LT11
LT11 / Letter 1058: Notice of Intent to Levy and Your Right to a Hearing
The IRS intends to seize your property unless you act. The same notice is issued as LT11, as Letter 1058 and as Letter 11.
Letter 3172
Notice of Federal Tax Lien Filing
IRS filed a public lien against your property
CP77
Notice of Intent to Levy and Your Right to a Hearing
The IRS says it intends to levy. The hearing comes before the levy on this one — the date is printed on the notice.
CP177
Notice of Intent to Levy and Your Right to a Hearing
The IRS says it intends to levy, and this is the notice on which it lists what it can take.
CP90C
Notice of Levy Already Made, and Your Right to a Hearing
The levy has already happened. The hearing right on this notice comes after it, not before.
CP297A
Notice of Levy Already Made — No Pre-Levy Hearing Because of an Earlier One
The levy has happened. The IRS says a hearing you requested in the last two years is why there was no hearing first.
CP297C
Notice of Levy Already Made — Federal Contractor, No Pre-Levy Hearing
The levy has happened. The IRS says federal contractors do not get a hearing beforehand — you get one after.
CP298
Notice of Intent to Levy Social Security Benefits
The IRS says it intends to take up to 15% of Social Security benefits. Calling Social Security will not stop it.
LT73
Notice That a Levy Was Issued for Unpaid Employment Tax
A levy has been issued over unpaid federal employment tax. Filings must be current before a payment plan is possible.
LT75
Notice That a Notice of Levy Was Issued
The IRS says it issued a notice of levy. The instructions on this one live on the letter, not on the IRS web page.
CP523
Intent to Terminate Your Installment Agreement and Levy
You have defaulted. The IRS states a deadline here — no later than 30 days from the date of the notice.
CP508C
Your Tax Debt Has Been Certified to the State Department
The IRS has told the State Department your debt is seriously delinquent. A passport can be denied or revoked on that basis.
Urgent Notices
Time-sensitive notices that need your attention soon.
CP92
Notice of Levy on Your State Tax Refund
The IRS has already levied your state tax refund. Unlike most levy notices, this one arrives after the fact — and it carries a right to a hearing.
CP504B
Notice of Intent to Levy — business
The business version of CP504. It states a 30-day period, and names two levy types the IRS may serve without a further notice.
CP503
Second Reminder Notice
Urgent reminder - action required immediately
Letter 2501
Proposed Assessment - Balance Due
IRS proposes you owe taxes after review
CP242
Notice That Your State Tax Refund Was Taken, and Your Right to a Hearing
The IRS took a state tax refund to pay a federal balance. The hearing right on this notice comes after the fact.
LT16
Unpaid Taxes or Missing Returns, With Enforcement Named
The IRS names what enforcement means on this one: seizing assets or wages, and a lien that can affect credit.
LT18
Overdue Tax Returns, With a Ten-Day Filing Instruction
The IRS asks for the missing return within 10 days of the letter date. That number is published, and it is short.
LT26
File Your Tax Returns Immediately — Ten Days From the Notice Date
The IRS asks for the missing returns within 10 days. It also states the deadline for claiming a refund on a late return.
LT27
Your Payment Plan Application Was Not Received
The IRS started a payment plan application and did not get it. If you do not respond, the account goes back to collections.
CP522
The IRS Is Reviewing Your Installment Agreement
Call by the date on the notice, with Form 433-F filled in. Do not mail the form — the IRS says it will not arrive in time.
CP523H
Intent to Terminate a Shared Responsibility Payment Agreement
The CP523 for a Shared Responsibility Payment balance. Same 30 days, different balance, and no lien or levy language.
CP2566
Proposed Assessment from a Return You Didn't File
The IRS calculated a tax, penalty, and interest figure itself, from third-party wage and income data, because no return was filed.
CP538
Second Notice — Backup Withholding on Interest or Dividend Income
States a real consequence a first notice does not: if the IRS doesn't hear from you by the date on the notice, backup withholding begins or continues.
Warning Notices
These indicate a problem that needs to be addressed.
CP14
Balance Due Notice
The IRS says you owe money on unpaid taxes. The due date is printed on the notice — this page cannot tell you what it is.
CP501
Reminder Notice
First reminder that you still owe taxes
CP2000
Underreporter Notice
IRS records do not match your return
CP11
Changes to Your Tax Return
IRS made changes that result in additional tax due
CP22
Changes to Your Return - Refund Reduced or Owe More
IRS adjusted your return and now you owe or get less refund
CP23
Estimated tax payments corrected — balance due
The IRS found a difference between the estimated tax payments on your return and what it posted to your account. The IRS states this leaves a balance due.
Letter 2205
IRS Needs Additional Information
IRS requests more information about your return
LT14
Unpaid Balance or Past Due Return, and the IRS Could Not Reach You
The IRS says it has an unpaid balance or a missing return for you and has not been able to make contact.
LT19
The IRS Is Collecting an Unpaid Balance
A collection letter with a payment voucher attached, and a hearing right the IRS points to the notice for.
LT38
Collection Notices Are Resuming After the Pandemic Suspension
The IRS suspended some collection notices during the pandemic and is restarting them. It states this is not an audit.
LT39
The Annual Reminder the IRS Is Required by Law to Send
The IRS states it is required by law to remind you in writing. It also describes what Currently Not Collectible does and does not do.
LT40
The IRS Intends to Contact Other People About You
Third-party contact. The IRS states what it will tell them, for how long, and that you get a list of who it contacted.
CP166
Your Direct Debit Payment Could Not Be Taken
The IRS could not withdraw the monthly payment. It will keep trying even if you also mailed one.
CP40
Your Account Was Assigned to a Private Collection Agency
A private firm will contact you about an IRS debt. This is the notice that tells you it is legitimate, and how to check.
CP140
Your Overdue Business Account Was Assigned to a Private Collection Agency
The business version of CP40, with a different verification method: you give five digits, the agency gives five back.
CP94
Court-Ordered Restitution Balance Due
A court, not the IRS, ordered this amount. The IRS is collecting it, and interest applies only if the court ordered interest too.
CP59
We Have No Record You Filed — First Notice
The IRS says it has no record of a prior-year return. Unlike a balance-due notice, no amount owed has been established yet.
CP88
Refund Held Pending an Unfiled Return
The IRS is holding your refund, not applying it to anything yet, because it believes you have an unfiled return and may owe tax.
CP162
Penalty for Not Filing Electronically as Required
A penalty notice, not a balance-due reminder. The IRS charged this because a return that had to be e-filed was not.
CP2501
Underreporter Inquiry — Income Doesn't Match
The step before a CP2000. The IRS states this isn't a bill, but you must respond.
CP540
You May Be Subject to Backup Withholding
The trigger notice for backup withholding on interest or dividend income, tied to an unfiled return or unreported income.
CP230
Employment Tax Adjusted for an Information Return Mismatch
A business notice with a real 30-day dispute window: the IRS changed a return because information returns didn't match employment tax returns.
Informational Notices
General information or requests from the IRS.
CP21
Changes to Your Return Adjusted Your Refund
IRS changed your refund amount
CP49
Overpayment Applied to Other Tax Debt
Your refund was used to pay another tax debt
CP71A
Annual Reminder of Balance Due
Annual notice that you still owe taxes
CP71C
Annual reminder of an unpaid balance
Annual reminder while on payment plan
LT33
Your Payment Was Applied and a Balance Remains
A payment landed. It did not clear the account. This notice is the difference.
CP521
Your Installment Agreement Payment Is Due
A monthly reminder on an existing agreement. Missing it is how an agreement defaults.
CP508R
Your Seriously Delinquent Certification Has Been Reversed
The IRS has told the State Department the certification is reversed. It states you do not need to respond.
CP44
Refund Delayed While the IRS Checks for Other Debts
A holding notice, not a collection notice. The IRS states you don't need to do anything while it checks whether you owe other federal tax.
Letter 3164
Notice of Third-Party Contact
A rights notice, not a payment demand. The IRS is telling you it plans to contact people like a neighbor, bank, or employer about your tax liability.
CP542
Backup Withholding Stopped
The reversal notice. It confirms backup withholding has ended and tells you what to do if a payer didn't get the message.
CP39
Refund Applied to a Spouse's or Former Spouse's Tax Debt
A refund from you, your spouse, or a former spouse was used to pay a past-due tax debt. You might still owe money.
CP128
Remaining Balance After an Overpayment Was Applied
A business-account notice: an overpayment (offset-in) from one tax period was applied to another, and a balance is still due.
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