Where and how to report suspected tax fraud

The IRS has a dedicated channel for reporting suspected tax fraud: the Form 13909, "Information Referral." You can file it online through the IRS website, mail it in, or fax it. The online form is the fastest route — you fill it out on IRS.gov, submit it, and receive a confirmation number. If you mail it, send Form 13909 to the IRS Criminal Investigation office address listed on the form itself, which varies by region. Faxing is also an option if you have the specific fax number for your local IRS office.

You do not need to be a tax professional or have proof before you report. The IRS accepts reports based on suspicion alone. What matters is that you provide as much detail as you can: the person's or business's name, address, phone number, what type of fraud you suspect (underreporting income, false deductions, cash-only businesses not reporting sales), and when you noticed it. If you have documents — a receipt, a bank statement, a screenshot of an ad — include copies, not originals.

The IRS also accepts reports through its online whistleblower portal at IRS.gov/Fraud. This route is useful if you want to track your report or if you have substantial documentation to upload. Reports submitted this way go to the same investigators but create a case file you can reference later if needed.

Key Takeaways

  • Form 13909 is the official IRS form for reporting tax fraud, and you can submit it online, by mail, or by fax.
  • You do not need proof or certainty — the IRS accepts reports based on suspicion and investigates from there.
  • Provide as much identifying information as possible: the person's name, address, business details, and what type of fraud you suspect.
  • The IRS online whistleblower portal lets you upload documents and track your report if you have substantial evidence.
  • Reports are confidential; the IRS does not disclose your identity to the person you report.

What information to include in your report

Start with identifying details. If you are reporting a person, provide their full name, address, phone number, and Social Security number if you know it. If it is a business, include the business name, address, phone number, and Employer Identification Number (EIN) if visible. The more specific you are, the easier it is for investigators to locate the right entity.

Next, describe what you observed. Be concrete: "The business advertises cash-only services but I have never seen them file a tax return" or "The person claims $50,000 in charitable deductions but I know they donated used clothing worth maybe $2,000." Vague suspicions like "I think they are hiding money" are harder to investigate. Specific observations — dates, amounts, documents you have seen — give investigators a starting point.

Include any documents you have: bank statements, receipts, invoices, emails, screenshots of social media posts showing expensive purchases, or business advertisements. You can attach these to the online form or include copies with a mailed Form 13909. Do not send originals; keep those for yourself in case you are contacted for follow-up questions.

Reporting fraud you witnessed at work or in a business relationship

If you discovered the fraud as an employee, contractor, or business partner, your report carries more weight because you have direct knowledge. Include your role: "I worked as a bookkeeper for three years" or "I was a vendor who invoiced them monthly." Explain how you learned about the fraud — did you see the books, handle the money, or notice discrepancies in what was reported versus what you observed?

You can report anonymously through Form 13909, but if you are willing to be contacted, provide your phone number or email. The IRS may need clarification on details, and being reachable speeds up the investigation. Your identity is protected; the IRS does not share your name with the person or business you report.

If the fraud involves your employer and you are concerned about retaliation, you can still report it. Federal law protects whistleblowers in certain situations, though protections vary by industry and the type of fraud. The IRS can advise you on this when you file your report.

What happens after you submit a report

The IRS Criminal Investigation division receives your report and assigns it to an agent if it meets their criteria for investigation. This does not happen immediately — the IRS receives thousands of reports and prioritizes based on the amount of money involved, the type of fraud, and how clear the evidence is. A report about a small business underreporting $5,000 in income may take months to reach an agent, if it does at all. A report about a scheme involving hundreds of thousands of dollars moves faster.

You will not hear back from the IRS about the status of your report unless you provided contact information and the agency needs more details from you. If you filed online through the whistleblower portal, you can log in to check whether your case has been assigned. If you mailed Form 13909, you receive a confirmation number but no further updates unless you contact the IRS directly.

Investigation timelines vary widely. Some cases close within months; others take years. The IRS does not notify you when an investigation concludes or what the outcome was, even if you were the person who reported it. You may learn about results if they become public — for instance, if criminal charges are filed or a settlement is announced — but the IRS does not provide individual case updates to reporters.

Reporting fraud you suspect but did not witness directly

You can report fraud based on secondhand information, rumors, or patterns you noticed. For example, you might report a neighbor whose lifestyle does not match their reported income, or a social media influencer who never mentions paying taxes. The IRS takes these reports seriously because they often point to real problems, but be clear about what you actually know versus what you are inferring.

In your report, separate fact from suspicion: "I know they earn money from social media because they post sponsored content daily" (fact) versus "I assume they are not reporting it because I have never heard them mention taxes" (inference). Investigators can work with both, but they need to know which is which.

If your suspicion is based on something you read online or heard from someone else, say so. Include the source if you can — a news article, a social media post, a conversation with a coworker. This helps investigators understand the basis for your report and decide whether to pursue it.

Other ways to report tax fraud

If the fraud involves identity theft — someone using your Social Security number to file a false tax return — report it to the IRS Identity Theft Hotline at 1-800-908-4490. This is a separate process from Form 13909 because identity theft requires immediate action to protect your account and prevent future filings in your name.

If the fraud is connected to a specific IRS program — such as someone falsely claiming the Earned Income Tax Credit or the Child Tax Credit — you can still use Form 13909, but mention the program in your description. This helps the IRS route your report to the right team.

Some fraud is also a crime under state law. If you want to report it to state authorities as well, you can contact your state's Attorney General office or local law enforcement. Reporting to both the IRS and state authorities does not create a conflict; they coordinate on cases that cross jurisdictions.

Frequently Asked Questions

Can I report tax fraud anonymously?

Yes. Form 13909 does not require your name or contact information. You can submit it online or by mail without identifying yourself. However, if you provide contact details, the IRS can reach you if they need clarification, which can speed up investigation. Your identity is kept confidential either way.

What if I am not sure whether it is actually fraud?

Report it anyway. The IRS distinguishes between fraud (intentional deception) and mistakes or aggressive tax positions. You do not have to prove intent; you just describe what you observed. Investigators decide whether it meets the threshold for fraud. Reporting something that turns out to be legal is not a problem.

Will the IRS tell me if they prosecute someone I reported?

Not directly. The IRS does not notify reporters of case outcomes. You may learn about it if the case becomes public — through news coverage or court records — but the IRS keeps individual reporter identities confidential and does not provide case updates.

Can I report someone if I am not a U.S. citizen?

Yes. You do not have to be a citizen or resident to report tax fraud to the IRS. If you are reporting fraud you witnessed while working in the U.S. or through a business relationship, your report is valid. Provide whatever identifying information you have.

What if the person I want to report is a family member?

You can report family members. The IRS does not have an exception for family relationships. Your report is confidential, so the person will not know it came from you unless the investigation becomes obvious or you tell them yourself.