The reference desk / Guide library
A clearer view of
what comes next.
317 guides. Start with the fundamentals, or jump straight to your letter. Looking for a specific notice? The letter index sorts all 289 by urgency.
Fundamentals & strategy
Fundamentals
Why You Should Never Ignore IRS Mail
That envelope from the IRS is not junk mail. Ignoring it can turn a manageable tax issue into a financial disaster.
Fundamentals
How to Identify Your IRS Letter or Notice Number
Every IRS letter has a code. Here is exactly where to find it and what the format means.
Deadlines
IRS Letter Deadlines You Cannot Afford to Miss
Some IRS deadlines are absolute. Miss them and you lose rights you can never get back.
Fundamentals
The Difference Between an IRS Notice and an IRS Letter
Notices and letters come from different parts of the IRS and mean very different things for your case.
Action Plans
What to Do the Moment You Receive an IRS Letter
A step-by-step action plan for the first 24 hours after you open an IRS letter.
Collections
The IRS Collection Notice Sequence: From First Notice to Levy
The IRS follows a specific escalation path before taking enforcement action. Here is every step.
Action Plans
7 Common Mistakes When Responding to IRS Letters
Most taxpayers make the same errors when dealing with IRS correspondence. Here is how to avoid them.
Collections
Can the IRS Levy Your Bank Account Without Notice?
The short answer is generally no. The IRS must follow a specific notice sequence before levying. Here is what that looks like.
Deadlines
The IRS Statutory Notice of Deficiency: The Most Important Letter You Will Ever Receive
The 90-day letter is your last chance to challenge the IRS before paying. Miss the deadline and you lose your day in court.
Identity
IRS Identity Verification Letters Explained
The IRS is increasingly aggressive about verifying your identity before processing returns. Here is what those letters mean.
Audits
IRS Audit Letters: What to Expect at Every Stage
From the initial contact letter to the closing letter, here is every piece of correspondence you will receive during an IRS audit.
Notices
Understanding the IRS CP2000 Notice
The CP2000 is one of the most common IRS notices. It proposes changes to your return based on income the IRS thinks you did not report.
Penalties
How to Request IRS Penalty Abatement After Receiving a Penalty Notice
IRS penalties are not always final. There are legitimate ways to have them reduced or removed entirely.
Collections
IRS Installment Agreement Letters: What They Mean for Your Payment Plan
Once you set up a payment plan with the IRS, the letters keep coming. Here is what each one means.
Identity
IRS Letters About Identity Theft: The CP01 Series
If someone filed a tax return using your Social Security number, the IRS has a series of letters to address it.
Non-Filer
The IRS Non-Filer Letter Sequence: What Happens When You Do Not File
The IRS knows when you do not file. Here is the escalating sequence of letters they send before filing a return for you.
Appeals
The IRS Appeals Process Explained Through the Letters You Receive
IRS Appeals is the most underused resolution tool in tax controversy. Here is how it works and what correspondence to expect.
Refunds
Why the IRS Is Holding Your Refund: Refund Hold Letters Explained
Your refund is delayed and the IRS sent you a letter. Here is what is happening and how to get your money.
Collections
The IRS Trust Fund Recovery Penalty: Letters That Can Change Your Life
If you are responsible for a business that owes payroll taxes, the IRS can come after you personally. Here are the letters that signal it.
Collections
What Is a Collection Due Process Hearing and Why the IRS Letter Matters
A CDP hearing is your legal right to challenge IRS collection actions. The letter that triggers it has a hard 30-day deadline.
Business
IRS Letters Every Business Owner Should Know
Business owners receive a different set of IRS letters than individual taxpayers. Here are the ones that matter most.
Notices
IRS Math Error Notices: When the IRS Changes Your Return Without an Audit
The IRS can change your return through the math error process, and your rights are more limited than you think.
Fundamentals
How to Read Your IRS Account Transcript to Understand Your Letters
Every IRS letter is reflected on your account transcript. Learning to read the transcript gives you the full picture.
Collections
IRS Offer in Compromise Letters: From Submission to Acceptance
The OIC process generates its own set of letters. Here is what to expect at every stage.
Compliance
IRS Digital Asset and Cryptocurrency Letters: What They Mean for You
The IRS is cracking down on unreported cryptocurrency. These letters tell you how serious they are.
Collections
How Long Does the IRS Have to Collect? Understanding the CSED and IRS Letters
The IRS has a limited time to collect tax debts. Understanding the collection statute can change your entire strategy.
Collections
IRS Passport Revocation Letters: When Tax Debt Grounds You
If you owe more than a certain amount, the IRS can certify your debt to the State Department and have your passport revoked or denied.
Action Plans
When to Hire a Tax Attorney for Your IRS Letter
Not every IRS letter requires professional help. But some absolutely do. Here is how to tell the difference.
Letter-by-letter guides
All 289, alphabetical. Color rail shows urgency. See the triage view for the full breakdown.
- CP01Identity Theft Claim Verified
- CP01AIP PIN Assigned
- CP01BAdditional Information Needed for ID Theft
- CP01CIdentity Theft Case Update
- CP01EEmployment-Related Identity Theft
- CP01HAccount Locked | SSN of Deceased Person
- CP01SWe Received Your Identity Theft Claim
- CP02You May Not Be Entitled to EITC
- CP04Proof Needed for Combat Zone Tax Deferment
- CP05Your Return Is Under Review
- CP05ADocumentation Needed to Verify Return
- CP06Premium Tax Credit Adjustment
- CP06APremium Tax Credit Changes Affecting Refund
- CP07Refund Held to Review Treaty Benefits or Itemized Deductions
- CP08You May Qualify for Additional Child Tax Credit
- CP09You May Qualify for Earned Income Credit
- CP10Overpayment Applied to Estimated Tax
- CP10AEstimated Tax Underpayment Penalty Waived
- CP11Balance Due From Return Processing Changes
- CP11ABalance Due From Processing Changes With Penalty
- CP12Math Error Corrected
- CP13No Refund, No Balance Due
- CP14What It Means and What to Do
- CP14HACA Shared Responsibility Payment
- CP14IBalance Due With Interest Detail
- CP15BTrust Fund Recovery Penalty Assessed Against You
- CP16Return Errors Corrected | Refund Changed
- CP20Tax Credit Adjustment
- CP21AAccount Adjusted | You May Owe
- CP21BAccount Adjusted | Refund Due
- CP21CAccount Adjustment | Math Error or Correction
- CP22AChanges to Your Return | Balance Due
- CP22EReturn Changes | No Balance or Refund Impact
- CP22IAlso covers CP21IIRA Tax Changes to Your Return
- CP23Estimated Tax Payment Mismatch
- CP24Estimated Payment Discrepancy | Refund Affected
- CP24EEstimated Payment Adjustment | No Change
- CP25Estimated Tax Payments Partially Credited
- CP25ARefund Held | Reconciling Estimated Payments
- CP27Earned Income Credit Reduced or Removed
- CP30Estimated Tax Penalty
- CP30AEstimated Tax Penalty Adjusted
- CP31Refund Check Returned
- CP32Refund Frozen | Injured Spouse May Apply
- CP32ARefund Applied to Spouse's Debt
- CP39Overpayment Applied to Other Tax Periods
- CP40Account Assigned to a Private Collection Agency
- CP42Refund Reduced for Past-Due Obligations
- CP44Refund Held Pending Return Review
- CP45Overpayment Applied to Next Year's Estimated Tax
- CP49Refund Applied to Another Tax Year
- CP51ABalance Due on Form 1040
- CP51BBalance Due | Second Notice
- CP51CBalance Due | Third Notice
- CP52Self-Employment Tax Correction
- CP53Refund Delayed
- CP53ARefund Further Delayed
- CP53BRefund Delayed | Additional Review Needed
- CP53CRefund Delayed | System Issue
- CP53EUpdate Bank Information for Your Refund
- CP54BAlso covers CP54QName and SSN Mismatch Is Holding Your Refund
- CP54EName and SSN Do Not Match on Estimated Tax Payments
- CP54GName and SSN Mismatch on a Return With No Refund
- CP57Bad Check Penalty
- CP59We Don't Have a Record of Your Return
- CP60Payment Not Found or Not Credited
- CP63Refund Frozen for Unfiled Returns
- CP71Annual Reminder of Balance Due
- CP71AAnnual Balance Reminder With Payment Options
- CP71CAnnual Reminder | Currently Not Collectible
- CP71DAnnual Reminder That You Still Owe
- CP71HAlso covers CP501HUnpaid Shared Responsibility Payment
- CP74You Are Recertified to Claim Your Credits
- CP75EITC Under Examination
- CP75AEITC Review | Additional Time Needed
- CP75DEITC Recertification Required
- CP75EVerify the Letter Number
- CP77Intent to Levy Your Alaska Permanent Fund Dividend
- CP79EITC Banned
- CP79AMultiple Credits Banned
- CP80Credit on Account, Return Not Filed
- CP80AEstimated Tax Credit | Return Not Filed
- CP81Unfiled Return, Credit About to Expire
- CP87ASomeone Else Claimed Your Dependent
- CP87BSomeone Else Claimed You as a Dependent
- CP87CYour Dependent Had Too Much Income
- CP88Refund Held for Delinquent Returns
- CP90Final Notice of Intent to Levy
- CP91Intent to Levy Social Security Benefits
- CP92State Tax Refund Levied
- CP104Address Change Verification
- CP120ATax-Exempt Status Automatically Revoked
- CP121Late Form 1120-F Filed by a Foreign Corporation
- CP134Employer Tax Overpayment Applied
- CP134BEmployer Account Adjustment
- CP136Penalty Removed From Account
- CP136BYour Form 941 Deposit Schedule for Next Year
- CP141Refund Applied to Balance Due
- CP141CAdditional Refund Applied to Balance
- CP141LLate Filing Penalty on an Exempt Organization Return
- CP161Penalty Balance Due
- CP162Late Filing Penalty for Business Returns
- CP162APenalty for a Late Partnership or S Corporation Return
- CP166Direct Debit Installment Payment Returned for Insufficient Funds
- CP169We Are Missing Your Return
- CP171Annual Balance Due Reminder | Business
- CP187Business Return Penalty Assessed
- CP210Business Account Adjusted | Balance Due
- CP214Reminder to Review Your Form 5500-EZ Filing Requirement
- CP215Business Penalty Assessed
- CP216Schedule K-1 Processing Issue
- CP220Business Account Penalty or Interest Change
- CP220JEmployer Shared Responsibility Bill
- CP231Refund Sent to Old Address
- CP234Premium Tax Credit Adjusted
- CP256VACA Employer Shared Responsibility Payment
- CP259Business Return Not Filed
- CP261S Corporation Election Accepted
- CP267Credits on Your Business Return Do Not Match
- CP268Math Error Created an Overpayment on Your Business Return
- CP276ATax Liability Schedule Problem, Deposit Penalty Waived
- CP276BLate Federal Tax Deposits, Penalty Waived This Time
- CP283Penalty for a Late or Incomplete Form 5500-EZ
- CP295Unpaid Penalty for a Late or Incomplete Form 5500
- CP297Final Levy Notice for Businesses
- CP297ALevy Issued and Post-Levy CDP Rights
- CP298Intent to Levy Up to 15% of Social Security for Business Taxes
- CP501First Reminder of Balance Due
- CP502Second Balance Due Reminder
- CP503Second Balance Due Reminder
- CP504Intent to Levy
- CP504BIntent to Levy | Passport at Risk
- CP508CPassport Certification
- CP515Also covers CP518Non-Filer Escalation Notices
- CP521Installment Agreement Payment Reminder
- CP522Your Installment Agreement Is Under Financial Review
- CP523Your Installment Agreement Is About to Default
- CP531You May Become Subject to Backup Withholding
- CP565Your ITIN Has Been Assigned
- CP566Identity Theft Case Acknowledged
- CP567ITIN Application Rejected
- CP575EIN Confirmation and Digital Verification
- CP2000Underreported Income
- CP2005Underreporter Case Closed | No Change
- CP2006Underreporter Response Accepted
- CP2057Return Information Doesn't Match IRS Records
- CP2100First B-Notice for Backup Withholding
- CP2100ATIN Mismatches and Backup Withholding
- CP2501Underreporter Follow-Up
- CP2566Substitute for Return
- CP2566RSubstitute for Return | Refund Held
- CP3219AStatutory Notice of Deficiency
- CP3219NNonfiler Statutory Notice of Deficiency
- Form 668(Y)Notice of Federal Tax Lien
- Form 4564Information Document Request
- Letter 12AVerify the Letter Number
- Letter 12CMissing Information to Process Your Return
- Letter 12DVerify the Letter Number
- Letter 12EIdentity or Account Verification
- Letter 86CInquiry Transferred to Another Office
- Letter 96Appeals Case Acknowledged
- Letter 105CFormal Claim Disallowance
- Letter 106CClaim Partially Disallowed
- Letter 107CVerify the Letter Number
- Letter 112CResponse to Taxpayer Inquiry
- Letter 147CVerification of an Existing EIN
- Letter 148CInstallment Agreement Accepted
- Letter 168CPenalty Removed or Reduced
- Letter 170CPayment Acknowledged
- Letter 177CInstallment Agreement Terms or Changes
- Letter 203CInformational Response
- Letter 220Verify the Letter Number
- Letter 226-JProposed Employer Shared Responsibility Payment
- Letter 227-JEmployer Payment Agreement Acknowledged
- Letter 227-KEmployer Payment Reduced to Zero
- Letter 227-LRevised Employer Payment Proposal
- Letter 227-MEmployer Payment Proposal Unchanged
- Letter 227-NEmployer Payment Result After Appeals
- Letter 227-ORevised Employer Payment for TE/GE
- Letter 227CAccount or Identity Verification Request
- Letter 239CResponse to Your Correspondence
- Letter 264CProcessing Delay Notice
- Letter 306CMath or Error Clarification
- Letter 321Appeals Case Status Update
- Letter 354CReturn or Account Adjustment Explained
- Letter 365CCollection Status Notice
- Letter 380Appeals Conference Scheduling
- Letter 431CVerify the Letter Number
- Letter 446CRefund Held Pending Verification
- Letter 488CVerify the Letter Number
- Letter 507CVerify the Letter Number
- Letter 525The 30-Day Letter After Audit
- Letter 531Notice of Deficiency
- Letter 544CCollection Activity Notice
- Letter 566Information Document Request
- Letter 585Verify the Letter Before Acting
- Letter 686CVerify the Letter Number
- Letter 692Additional Examination Findings
- Letter 725AVerify the Letter Number
- Letter 725BCollection Appointment
- Letter 725CVerify the Letter Number
- Letter 854CAdditional Verification Request
- Letter 91530-Day Examination Letter
- Letter 916CClaim Not Considered
- Letter 95030-Day Letter (Audit/Appeals)
- Letter 979Inadequate Records Notice
- Letter 1058Final Notice Before Levy
- Letter 1153Proposed Trust Fund Recovery Penalty
- Letter 1615Verify the Letter Number
- Letter 1962Direct-Debit Installment Agreement Granted or Revised
- Letter 2030Proposed Business Return Changes
- Letter 2205AField Audit Notification
- Letter 2272CAccount Verification
- Letter 2273CIdentity Verification
- Letter 2275CAdditional Authentication Required
- Letter 2439Refund Offset Notice
- Letter 2518Offer in Compromise Payment Reminder
- Letter 2531Business Return Information Mismatch
- Letter 2645CProcessing Delay Response
- Letter 2781CAccount Issue
- Letter 2788CAccount Issue Resolved
- Letter 2797CRefund Inquiry Response
- Letter 2800CPenalty Abated or Account Adjusted
- Letter 2801CPenalty Relief Granted
- Letter 2802CEmployment Tax Adjustment
- Letter 2808CWithholding Lock-In Modification
- Letter 2840COffer in Compromise Accepted
- Letter 3027Verify the Letter Before Acting
- Letter 3064CExamination Closed | No Change
- Letter 3164Notice of Third-Party Contacts
- Letter 3172Notice of Federal Tax Lien Filing
- Letter 3176CFrivolous Return Warning
- Letter 3219Statutory Notice of Deficiency (90-Day Letter)
- Letter 3219AAutomated Underreporter Deficiency Notice
- Letter 3219BBusiness Mismatch Deficiency Notice
- Letter 3219CWage, Withholding, or Credit Deficiency Notice
- Letter 3284CNon-Requesting Spouse Initial Contact
- Letter 3286CAccount Action Confirmation
- Letter 3311Appeals Decision Letter
- Letter 339130-Day Non-Filer Letter
- Letter 3477Installment Agreement Terms
- Letter 3572Audit Closed | No Change
- Letter 3586Trust Fund Recovery Penalty Interview
- Letter 3657CInnocent Spouse Claim Not Considered
- Letter 3708FBAR Penalty Notice and Demand
- Letter 4112CVerify the Letter Number
- Letter 4141Collection Appeals Program Decision
- Letter 4281Return Received Confirmation
- Letter 4384CReturn Under Review or Hold
- Letter 4464CReturn Selected for Review
- Letter 4800CQuestionable Wages and Withholding Review
- Letter 4883CAlso covers Letter 6330CVerify Your Identity by Phone
- Letter 5071CAlso covers CP5071 · CP5071F · Letter 6331CIdentity Verification
- Letter 5072CIdentity Theft Case Update
- Letter 5073CIdentity Theft Case Resolved
- Letter 5263CAlso covers Letter 6042CEntity Verification
- Letter 5447CPower of Attorney Processed
- Letter 5471Verify the Letter Number
- Letter 5699Missing ACA Information Returns
- Letter 5747CIn-Person Identity Verification
- Letter 5775Interview About Another Tax Matter
- Letter 5938Missing Individual Income Tax Return
- Letter 6167CIdentity Authentication Incomplete
- Letter 6173Digital Asset Compliance
- Letter 6174Digital Asset Education Letter
- Letter 6174-ADigital Asset Follow-Up
- Letter 6176Exempt Organization Compliance Issue
- Letter 6201Tax Compliance Report
- Letter 6217CEntity Verification Follow-Up
- Letter 6574Business Tax Compliance Report
- LT11Final Notice of Intent to Levy
- LT14Unable to Reach You
- LT16Unpaid Taxes or Missing Returns
- LT17Refund Applied to Outstanding Balance
- LT18Installment Agreement Pending
- LT19Balance Update
- LT21Account Status Letter
- LT22Balance Due With Payment Options
- LT23Verify the Letter Number
- LT24More Information Needed for a Payment Plan
- LT26Overpayment Applied to Balance
- LT27Account Adjusted | No Balance Due
- LT33Refund Applied to Balance Due
- LT38Account Balance Statement
- LT39Currently Not Collectible Status Confirmed
- LT40IRS Intends to Contact Third Parties
- LT41Third Party Contact | Unfiled Returns
- LT73Levy for Unpaid Employment Taxes
- LT75Levy Issued for Unpaid Taxes