Quick summary

This article explains how to authenticate an IRS letter, step-by-step checks to spot fraud, where to verify official notices, and what to do if you think a communication is fake. I draw on more than 15 years helping clients with tax notices and identity-theft recovery, so you’ll find practical actions you can take immediately.

Why authenticating IRS mail matters

Scammers increasingly impersonate the IRS to steal money and personal information. The real IRS communicates primarily by U.S. mail, and its legitimate notices follow consistent formats and procedures. Confirming authenticity protects you from payment scams (gift cards, wire transfers, prepaid cards), identity theft, and emotional pressure that leads to bad decisions. The IRS and consumer protection agencies continue to warn taxpayers about impersonation schemes (IRS, 2025; FTC, 2025).

Step-by-step checklist to authenticate an IRS letter

  1. Pause and don’t respond immediately
  • Scammers rely on panic. Take a breath and follow the verification steps below.
  1. Look for the notice or letter number
  • Official IRS letters include a notice or letter ID (for example, CP or LT codes) printed in the top right or top center. Note the code and the date — these are the quickest ways to identify the type of communication.
  • Use the IRS website search to look up that specific notice code and wording (IRS Notice/Letter Glossary). If you can’t find it, treat the letter as suspicious.
  1. Confirm the return address and sender details
  • Compare the return address to IRS addresses listed on IRS.gov. The IRS sends mail from several centralized processing centers; the exact address varies by notice type and state.
  • Missing or generic return addresses, foreign addresses, or PO boxes that don’t match IRS formats are red flags.
  1. Inspect payment requests and methods
  • The IRS will never demand immediate payment via gift cards, prepaid debit cards, cryptocurrency, or payment to a third-party escrow or offshore account.
  • Legitimate IRS notices give options: pay online (through IRS-authorized processors), mail a check, or call an IRS number—never demand unusual payment channels.
  1. Read the greeting and tone
  • Authentic IRS letters normally use your full legal name and a professional tone. Letters that begin with “Dear Taxpayer” without your name, contain typos, or threaten immediate arrest are likely scams.
  1. Verify content with IRS resources
  • Don’t use phone numbers or URLs in the suspicious letter. Instead, go to IRS.gov and search the notice code or the key phrases appearing in the letter. The IRS publishes examples of legitimate notices and official guidance on identifying impersonation scams (see IRS link below).
  1. Check your IRS online account
  • If you’ve registered for an IRS online account, log in (at IRS.gov) to see correspondence the IRS has sent you. The IRS sometimes lists notices there, which provides direct confirmation.
  1. Call the IRS using contact information from IRS.gov
  • If the issue is urgent or unclear, call the IRS at the phone number listed on IRS.gov for individual taxpayers rather than numbers printed or offered in the suspect letter. Expect limited wait times and follow official prompts.
  1. Use identity-protection tools if needed
  • If you suspect identity theft, apply for or verify your Identity Protection PIN (IP PIN) through the IRS Get an IP PIN tool (IRS.gov). The IP PIN helps stop others from filing fraudulent returns using your Social Security number.
  1. Keep records and report the attempt
  • Save the letter and any related emails or texts. Report scams to the IRS, the Treasury Inspector General for Tax Administration (TIGTA), and the Federal Trade Commission (FTC) so agencies can investigate and warn others.

Common red flags that mean a letter may be fake

  • It demands immediate payment to avoid arrest or deportation.
  • Payment is required via gift cards, cryptocurrency, prepaid debit cards, or to a private bank account.
  • The sender calls or texts before sending a mailed notice and pressures for instant payment.
  • The letter has poor grammar, spelling mistakes, or unusual formatting.
  • You are asked to provide sensitive information (full Social Security number, bank account passwords, login credentials) over the phone, email, or web form.

These behaviors are widely documented by the IRS and FTC as hallmarks of impersonation scams (IRS, “Don’t Fall for IRS Impersonation Scams”; FTC complaint guidance).

How to verify a specific notice or code

  • Note the notice/letter code and date. Search that code on IRS.gov; many notices have explanation pages or examples.
  • If the letter references a tax year or specific amount, cross-check your tax return and payment records for that tax year. Reconcile any mismatch before taking action.
  • If the notice is about unfiled returns, audits, or balances due and you cannot find the notice in your IRS online account, call the IRS using their official contact information.

For a deeper primer on notice timelines and next steps after receiving an IRS notice, see our guide: “Understanding the Timeline After an IRS Notice: Deadlines and Next Steps” (internal link: https://finhelp.io/glossary/understanding-the-timeline-after-an-irs-notice-deadlines-and-next-steps/).

If you already gave personal information or paid

  1. Contact your bank or the payment processor immediately to attempt a stop-payment or reversal.
  2. Report the crime to your local police and file complaints with the FTC (ReportFraud.ftc.gov) and TIGTA (TIGTA hotlines and online form).
  3. Place fraud alerts or credit freezes with the three major credit bureaus (Experian, Equifax, TransUnion).
  4. If tax-related identity theft is suspected, follow IRS guidance and file Form 14039 (Identity Theft Affidavit) if instructed by the IRS or if your e-file return was rejected because a return for your SSN was already filed.
  5. Consider enrolling in credit monitoring or identity-theft protection, especially if financial account details were exposed.

If you need help understanding IRS identity verification steps, our related article “What Every Taxpayer Should Know About IRS Identity Verification Procedures” explains the IRS process and timelines (internal link: https://finhelp.io/glossary/what-every-taxpayer-should-know-about-irs-identity-verification-procedures/).

Real-world example (typical case I’ve seen)

A client received a letter claiming she owed a large balance and must pay via prepaid debit cards. The letter used aggressive language and offered one phone number for questions. I reviewed the notice code and compared the return address to the IRS. The payment method and tone were immediate red flags. We called the IRS using the number on IRS.gov, confirmed no such notice had been issued, and reported the scam. The client avoided a six-figure loss and learned to verify future contacts before responding.

How the IRS legitimately contacts taxpayers (what to expect)

  • Mail is the IRS’s primary channel for official notices before collections or legal action. They usually send a paper letter first.
  • The IRS may call, but only after sending a mailed notice in many cases. If the IRS calls, it will not demand payment using odd payment methods and will provide a notice number and contact information.
  • The IRS will not ask for passwords, account PINs, or full financial login credentials.

For guidance on how to respond when the IRS calls, see our practical piece: “What to Do When the IRS Calls: Verifying Identity and Avoiding Scams” (internal link: https://finhelp.io/glossary/what-to-do-when-the-irs-calls-verifying-identity-and-avoiding-scams/).

Reporting suspicious IRS correspondence

  • Report phishing emails and suspicious electronic messages to the IRS at phishing@irs.gov and to the FTC at ReportFraud.ftc.gov.
  • For mail-based impersonation or threatening letters, file a complaint with TIGTA via its online complaint page (tigta.gov) and the FTC.
  • Keep a copy of the suspect letter and any related messages.

Professional tips I give clients

  • Create an IRS online account and check it periodically for official correspondence; it’s often the fastest way to verify a mailed notice.
  • Keep a running file of your tax returns and payment confirmations by year so you can quickly reconcile any alleged balance.
  • Teach older relatives and vulnerable family members to never send money or information in response to a threatening phone call or text; instead, call you or a trusted advisor first.
  • If in doubt, take a photo of the notice and text or email it to your tax professional for a quick second opinion.

In my practice, a short verification call to the IRS or a quick lookup of the notice code on IRS.gov prevents most costly mistakes.

Sources and further reading

Disclaimer

This article is educational and does not replace personalized legal, tax, or financial advice. If you’re unsure how to proceed with a specific notice or believe you’re a victim of fraud, consult a qualified tax professional or contact the IRS directly through the contact information on IRS.gov.