IRS Integrity and Verification Operations is the IRS unit that screens tax returns for identity theft, income and withholding errors, and questionable credit claims before any refund is paid. If your return is pulled by IVO, your refund is frozen and you’ll receive a specific numbered notice telling you either to wait, to verify your identity, or to send documentation supporting what you filed. It isn’t an audit. An IVO review looks at one thing: a single credit, the income and withholding on your return, or whether the person who filed is really you.
How an IVO Review Differs From an Audit
A traditional IRS examination gives the agency broad authority to request records across your entire return. IVO is narrower by design. Shortly after you file, automated systems compare your return against data the IRS already has from employers, banks, and schools. When numbers don’t match, or when a claim fits a known error pattern, the return is pulled for human review before the refund is released.
The mechanism exists because refundable credits like the Earned Income Tax Credit and Additional Child Tax Credit can pay out more than the filer’s total tax liability, so an incorrect claim costs the Treasury real money rather than just reducing a bill. Catching problems before the refund goes out is cheaper than clawing money back afterward.
Which Notice You Received
You won’t get a letter stamped “IVO.” You’ll get a numbered notice, and the number tells you what the IRS wants.
CP05: Wait
A CP05 says the IRS needs more time to verify your income, withholding, or credits. It does not ask you to do anything. The IRS instructs you to wait at least 60 days before contacting them.1Internal Revenue Service. Understanding Your CP05 Notice If the review clears internally, your refund is released without further action from you.
CP05A: Send Documentation
If the IRS can’t resolve the issue internally, it escalates to a CP05A, which does require a response. The notice asks for documents proving your income and federal tax withholding: at least three pay stubs including the year-end stub, a letter on company letterhead from your employer, or a statement of retirement benefits. The notice sets a response deadline, and after you send documents the IRS takes roughly another 60 days to finish the review.2Internal Revenue Service. Understanding Your CP05A Notice Don’t send a copy of your W-2. The IRS already has that; it’s looking for independent confirmation.
Identity Verification Letters
When the IRS suspects someone may have filed using your Social Security number, it sends one of three letters, each with its own response path:3Taxpayer Advocate Service. Identity Verification and Your Tax Return
- Letter 5071C is the most common. You can verify online through the IRS identity verification portal using an ID.me account, or by phone.4Internal Revenue Service. Verify Your Return
- Letter 4883C requires you to call the Taxpayer Protection Program hotline printed on the letter. Have the letter, the return in question, a prior-year return if you have one, and your W-2s and 1099s ready.5Internal Revenue Service. Understanding Your Letter 4883C
- Letter 5747C requires an in-person appointment at a Taxpayer Assistance Center. You must appear yourself, even if you have a representative. Bring a government-issued photo ID and the documents the letter lists.6Internal Revenue Service. Understanding Your Letter 5747C
Your refund won’t move until identity verification is complete. If you can’t find your letter, you can check your IRS online account or call the Taxpayer Protection Program line at 800-830-5084.
Why Returns Get Pulled
Flags aren’t random. A handful of patterns account for most IVO reviews.
- Data mismatches. Wages, interest, or other income on your return doesn’t line up with what employers and financial institutions reported on W-2s and 1099s. Small discrepancies are enough.
- Identity concerns. Multiple returns under one Social Security number, an unusual filing pattern for your history, or return data that doesn’t match IRS records.7Internal Revenue Service. What Taxpayers Should Do if They Get an Identity Theft Letter From the IRS
- Refundable credit eligibility. The most frequent trigger. Claiming the EITC, Additional Child Tax Credit, or American Opportunity Tax Credit when the underlying data doesn’t support it, for example an education credit without a matching Form 1098-T, or a dependent who doesn’t appear to meet the residency test.
- Head of household filing status. The IRS looks closely because the status carries a larger standard deduction and better brackets, so it wants proof you paid more than half the cost of maintaining the home.
Responding to the Notice
What you do next depends entirely on the notice. A CP05 needs patience. Everything else needs a clean, complete response the first time, because incomplete submissions restart the 60-day clock.
Verifying Identity
For 5071C and 4883C, the fastest path is online or by phone. Online verification runs through an ID.me account, which requires a government-issued photo ID and your Social Security number, and you must be at least 18.8Internal Revenue Service. Creating an Account for IRS.gov Have your original return in front of you; the system will ask about it. For 5747C, call the toll-free number on the letter to schedule the in-person appointment, and bring the ID and documents the letter lists.6Internal Revenue Service. Understanding Your Letter 5747C
Documenting Income and Withholding
For a CP05A or a similar income-verification request, send primary source documents. At least three pay stubs including the year-end stub, showing the date wages were earned, gross income, and federal tax withheld. A letter on company letterhead from your employer works as well.2Internal Revenue Service. Understanding Your CP05A Notice
If your employer closed, moved, or won’t respond, Form 4852 is the substitute wage statement. You’ll estimate income from pay stubs or a prior-year W-2 and explain in writing what you did to try to obtain the real W-2.9Internal Revenue Service. Using Form 4852 When Missing the Form W-2 or 1099-R
Proving Dependents and Residency
When dependents, head of household status, or EITC eligibility are at issue, you need documents that show both the qualifying relationship and shared residency. School records, medical records, and daycare statements showing the child’s name and your address all qualify. So does a letter on official letterhead from a school, doctor’s office, or social service agency showing names, a shared address, and dates.10Internal Revenue Service. Form 14824 – Supporting Documents to Prove Filing Status Leases or mortgage statements help establish the address itself.
Attach a cover sheet with the notice number and your Social Security number. Keep originals; send clear copies. Follow the submission instructions on the notice exactly, and if you mail documents use certified mail with a return receipt so you have proof if the IRS later says it never received your package.
Timelines and the PATH Act
Expect roughly 60 days from the time you submit documents for the IRS to finish reviewing them, longer during peak filing season.2Internal Revenue Service. Understanding Your CP05A Notice If nothing has arrived after 60 days, call the number on the original notice.
Separately, if you claimed the EITC or Additional Child Tax Credit, the Protecting Americans from Tax Hikes (PATH) Act bars the IRS from issuing your refund before mid-February, whether or not IVO flagged you.11Internal Revenue Service. When to Expect Your Refund if You Claimed the Earned Income Tax Credit or Additional Child Tax Credit Filed early with direct deposit and no issues, you can generally expect the refund by early March. An IVO review layered on top pushes that out further.
When the review closes, the IRS sends either a closing letter or a Notice of Adjustment. If your documentation holds up, the refund is released. If the credit or income is disallowed, the notice will explain the change and any resulting balance.
If You Don’t Respond
Ignoring an IVO notice is costly. For identity letters, the IRS simply won’t process your return or release your refund until you verify. There is no workaround. For credit and income notices, the IRS will disallow the items in question, cutting your refund or creating a balance due.12Internal Revenue Service. Understanding Your IRS Notice or Letter
After a disallowance, the IRS may issue a Notice of Deficiency, sometimes called a 90-day letter. That’s the formal notice that you owe more tax. You have 90 days from the date on the notice to file a petition with the U.S. Tax Court if you disagree, or 150 days if you live outside the country.13Internal Revenue Service. Understanding Your CP3219N Notice Miss that window and the tax is assessed. For disputes of $50,000 or less per tax year, Tax Court offers a simplified small-case procedure that doesn’t require a lawyer.14Office of the Law Revision Counsel. 26 USC 7463 – Disputes Involving $50,000 or Less Before it gets that far, you can file a written protest with the IRS Independent Office of Appeals within the time limit on your notice, generally 30 days.15Internal Revenue Service. Preparing a Request for Appeals
Penalties and Credit Bans
A disallowance can reach past the current year. If the IRS finds you underreported income or improperly claimed credits due to negligence, you may owe an accuracy-related penalty of 20 percent of the underpayment. A “substantial understatement” for individuals means the tax was understated by the greater of 10 percent of the correct tax or $5,000.16Internal Revenue Service. Accuracy-Related Penalty
The bigger long-term consequence is the credit ban. If the IRS determines your claim of the EITC, Child Tax Credit, or American Opportunity Tax Credit was due to reckless or intentional disregard of the rules, you’re barred from claiming that credit for two years. If the claim was fraudulent, the ban runs ten years.17Office of the Law Revision Counsel. 26 USC 32 – Earned Income Claim the credit during the ban and the IRS will reduce your refund using math-error authority, no full review needed.
After a ban ends, or after a credit was disallowed for a non-fraud reason, you’ll need to file Form 8862 with the return where you next claim the credit. Without it, the IRS rejects the claim automatically.18Internal Revenue Service. About Form 8862, Information To Claim Certain Credits After Disallowance
Interest on a Long-Delayed Refund
If IVO holds your refund long enough, the IRS owes you interest. By statute, interest accrues on refunds not issued within 45 days of the filing deadline, or 45 days after you filed if you filed late.19Office of the Law Revision Counsel. 26 USC 6611 – Interest on Overpayments The rate is set quarterly; it was 7 percent for the first quarter of 2026 and 6 percent for the second. You don’t have to ask for it. The IRS is supposed to add it automatically. If your refund took months, check the amount against your original return to make sure the interest is there.
When the Taxpayer Advocate Service Can Help
Most IVO reviews finish within a few months. Some stall. If the IRS keeps sending 60-day interim letters without resolving anything, or if a delayed refund is causing you real financial hardship, the Taxpayer Advocate Service can intervene. TAS takes cases involving economic harm, an immediate threat of adverse action, or an IRS process that hasn’t resolved within normal timeframes. If your issue has gone unresolved for more than 30 days past normal processing, or the IRS missed a date it promised, that qualifies as a systemic burden case TAS can accept.20Taxpayer Advocate Service. Submit a Request for Assistance
To request help, complete Form 911 and submit it to your local TAS office. Explain the notice you received, when you responded, what the IRS has done since, and why the delay is hurting you. If you don’t hear from TAS within 30 days, follow up with the office you submitted to. The service is free, and TAS can direct the IRS to expedite your case when circumstances warrant it.