The IRS sends an audit notice by U.S. mail, and only by U.S. mail. The first letter goes to the address on your most recently filed federal return, arrives as regular mail rather than certified, and carries an official Department of the Treasury header along with a letter or notice number on the first page. The agency does not open an audit by phone call, email, text message, or social media contact. If someone reaches you through any of those channels claiming your return is being audited, it is not the IRS.1Internal Revenue Service. How to Know Its the IRS
Being selected does not mean you did anything wrong. Fewer than 1 in 200 individual returns are examined in a typical year, and some are pulled at random.
Where the Letter Goes and How It Arrives
The IRS mails audit notices to your “last known address,” which under agency rules is the address on your most recently filed and properly processed return unless you’ve submitted a formal change-of-address notice. If you moved after filing and didn’t tell the IRS, the letter still goes to the old address. The agency has no obligation to track you down.
That first letter comes as ordinary mail. Certified or registered delivery is reserved for specific statutory notices later in the process, most importantly the Notice of Deficiency, which starts a 90-day legal clock to petition Tax Court.2Internal Revenue Service. IRS Audits After the initial letter arrives, an examiner may call you to schedule a meeting or ask a follow-up question. That contact is legitimate because it follows a mailed notice, not because a phone call ever starts an audit.1Internal Revenue Service. How to Know Its the IRS
What a Real Audit Notice Contains
The letter that actually opens an audit is typically a variant of Letter 566. Somewhere on the first page you’ll see that letter number printed, along with the tax year under review, a description of the specific items being examined, a response deadline, and instructions telling you exactly what to do next.3Taxpayer Advocate Service. Initial Contact Letter
The instructions depend on which of the three audit formats applies to you.4Taxpayer Advocate Service. What to Do if You Receive Notification Your Tax Return Is Being Examined or Audited
- A correspondence audit is handled entirely by mail. The letter lists the documents to send in and where to send them. This is the most common format, and most correspondence audits close within three to six months.5Internal Revenue Service. Publication 3498-A – The Examination Process (Audits by Mail)
- An office audit asks you to bring records to a local IRS office. The letter specifies the date, time, location, and the documents to bring.
- A field audit involves a revenue agent visiting your home or business. Field audits usually cover more complex returns with business income or multiple entities.
Every real notice will also show the IRS letterhead with the U.S. Department of the Treasury header and provide a phone number for questions. If you want to confirm the letter is authentic, call the number printed on the notice or sign in to your IRS online account at irs.gov, where official notices appear alongside your account.2Internal Revenue Service. IRS Audits Don’t call a number that came only from a suspicious letter; verify it independently first.
How to Tell a Real Notice From a Scam
Scammers impersonating the IRS keep changing tactics, but a short list of signals gives them away.1Internal Revenue Service. How to Know Its the IRS
- Initial contact by phone, email, text, or social media. The IRS mails you first, always.
- Demands for immediate payment, or threats of arrest, deportation, or license revocation.
- Requests for payment by gift card, prepaid debit card, or wire transfer.
- A caller who refuses to let you take time to verify their identity or consult a tax professional.
- Emails or texts claiming to be from the IRS that you didn’t specifically authorize.
You can report suspected scams to the Treasury Inspector General for Tax Administration at 1-800-366-4484 and forward suspicious emails to phishing@irs.gov.6U.S. Treasury Inspector General for Tax Administration. Submit a Complaint7Internal Revenue Service. Report Fake IRS, Treasury or Tax-Related Emails and Messages
One Legitimate Exception for Phone Contact
The IRS authorizes three private collection agencies (CBE Group Inc., Coast Professional Inc., and ConServe) to contact taxpayers about overdue tax debts. Before any of them calls, the IRS first mails Notice CP40 telling you your account has been assigned, and then the agency itself sends a letter. Both letters carry a taxpayer authentication number you can use to verify a caller.8Internal Revenue Service. Private Debt Collection
These agencies collect on existing balances only. They do not conduct audits. If someone calls claiming to be a private collector working for the IRS and you never received CP40, treat the call as a scam.
Other IRS Letters People Mistake for an Audit
Not every IRS envelope is an audit notice, and mistaking one type of letter for another leads people to panic over the wrong thing or ignore something serious.
CP2000 Is Not an Audit
A CP2000 is an automated notice generated when income reported by an employer or bank doesn’t match what appeared on your return. The IRS itself describes it as “not a bill.” You respond by either agreeing with the proposed change or explaining the discrepancy with documentation. No examiner is assigned, and no audit has been opened.9Internal Revenue Service. Understanding Your CP2000 Series Notice
Letter 525, the 30-Day Letter
Letter 525 arrives after an audit is already underway. It comes with an examination report showing the changes the examiner wants to make and gives you 30 days to agree, submit more documentation, or request an appeal.10Taxpayer Advocate Service. Letter 525 Audit Report/Letter Giving Taxpayer 30 Days to Respond
Letter 531 or 3219, the Notice of Deficiency
This one arrives by certified mail because it starts a 90-day countdown (150 days if you’re outside the U.S.) to petition U.S. Tax Court and contest the proposed tax without paying it first. Letter 531 is used for in-person audits; Letter 3219 covers mail audits. Miss the 90 days and the IRS can legally assess and collect.11Taxpayer Advocate Service. 90 Day Notice of Deficiency
What to Do After You Confirm the Notice Is Real
The worst move is to ignore the letter. The second worst is to respond in a rush without reading it or organizing your records.
Read the Whole Letter
Identify the tax year, the specific items being questioned, and the response deadline before doing anything else. All contact information and instructions are on the notice.2Internal Revenue Service. IRS Audits If the deadline is tight, you can usually request more time by calling the number on the notice before the due date.
Gather Only What’s Requested
You carry the burden of proving what’s on your return. The IRS expects receipts, canceled checks, bank statements, or bills to support reported income and deductions. Travel, entertainment, gift, and vehicle expenses need extra documentation, including contemporaneous logs and mileage records.12Internal Revenue Service. Burden of Proof Answer what the IRS asked about. Sending unrequested records for other parts of your return invites questions you didn’t have to answer.
Consider Getting Representation
You have the right to hire someone to handle the audit for you. Enrolled agents, CPAs, and attorneys all have unlimited representation rights before the IRS and can respond to letters or attend office audits on your behalf.13Internal Revenue Service. Understanding Tax Return Preparer Credentials and Qualifications If cost is an obstacle, Low Income Taxpayer Clinics can represent qualifying taxpayers in audits, appeals, and collection matters for free or at minimal cost. Publication 4134 lists clinics, or you can call 800-829-3676.14Internal Revenue Service. Low Income Taxpayer Clinics
Don’t Let the Deadline Pass
If the IRS doesn’t hear back on a correspondence audit, it generally will not send a second request. It disallows the items it questioned and moves toward issuing a Notice of Deficiency.15Taxpayer Advocate Service. Lifecycle of a Tax Return – Correspondence Audits Once that notice issues and the 90-day Tax Court window closes without a petition, the tax is assessed and collection begins: balance-due notices, potential liens, and eventually levies on bank accounts or wages. All of that follows from a letter that went unopened.