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The IRS Notice Library.

Received a letter from the IRS? Look up your notice or letter code below for a plain-English explanation, the deadline that matters, and exactly what to do next.

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CP14

Balance Due

Your first notice that you owe unpaid taxes, including penalties and interest.

CP501

Reminder of Balance Due

A reminder that you still have an unpaid balance on your account.

CP503

Second Reminder of Balance Due

A second, more urgent reminder that your balance is unpaid.

CP504Time-sensitive

Notice of Intent to Levy (State Refund)

An urgent notice that the IRS intends to levy your state tax refund and may pursue other assets.

LT11Time-sensitive

Final Notice of Intent to Levy

Your final notice before the IRS can levy your income and assets, and your right to a hearing.

CP90Time-sensitive

Final Notice of Intent to Levy

A final notice of intent to levy and a notice of your right to a Collection Due Process hearing.

CP297Time-sensitive

Final Notice of Intent to Levy (Business)

A final levy notice issued to businesses, with CDP hearing rights.

CP2000

Proposed Changes to Your Return

The income reported to the IRS does not match your return, and the IRS proposes changes.

CP2501

Income Does Not Match

An earlier-stage notice that income reported by third parties does not match your return.

CP22A

Data Processing Adjustment, Balance Due

The IRS changed your return based on information you provided, creating a balance due.

CP11

Miscalculation, Balance Due

The IRS corrected a math or entry error on your return, resulting in a balance you owe.

CP12

Correction, Refund Adjusted

The IRS corrected your return and changed your refund amount.

CP49

Refund Applied to Balance

Your refund was applied to a past-due tax balance from another year.

CP71C

Annual Balance Reminder

An annual reminder that you still owe a balance, often sent after a period of inactivity.

CP161

Balance Due, Request for Payment

A balance-due notice, frequently issued to businesses, requesting payment.

CP508CTime-sensitive

Seriously Delinquent Tax Debt (Passport)

Certification of a seriously delinquent tax debt to the State Department, which can affect your passport.

CP523Time-sensitive

Intent to Terminate Installment Agreement

Notice that the IRS intends to terminate your installment agreement for a missed or late payment.

CP90CTime-sensitive

Levy Notice After Prior Levy

A notice of levy issued when the IRS has previously levied and intends to levy again.

LT16Time-sensitive

Contact Us About Your Account

A request to contact the IRS about overdue taxes or unfiled returns, often from a revenue officer.

LT18Time-sensitive

Request for Unfiled Returns

A demand to file overdue tax returns immediately.

Letter 1058Time-sensitive

Final Notice of Intent to Levy

The final notice before levy, delivered by a revenue officer, with CDP hearing rights.

Letter 3172Time-sensitive

Notice of Federal Tax Lien Filed

Notice that the IRS has filed a public Notice of Federal Tax Lien, with hearing rights.

Letter 4883C

Verify Your Identity

The IRS needs to verify your identity before processing your return or refund.

CP05

We're Reviewing Your Return

The IRS is holding your refund while it reviews your return.

CP75

Audit of Your EITC or Credits

The IRS is auditing the credits (like the Earned Income Tax Credit) on your return.

CP2531

Business Income Mismatch

The income reported for your business does not match IRS records.

CP215

Business Penalty Assessed

A civil penalty has been assessed against your business.

CP71

Annual Reminder of Balance

An annual reminder of a balance you still owe, including accrued penalties and interest.

Letter 525

General 30-Day Audit Letter

Proposed audit changes with 30 days to respond before they become final.

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