Where and how to report suspected tax fraud

You can report suspected tax fraud to the Internal Revenue Service using Form 3949-A (Information Referral) or by submitting information online through the IRS website. The IRS Criminal Investigation division handles reports of deliberate tax evasion, false deductions, unreported income, and other intentional violations. You do not need to be certain — the IRS investigates based on the information you provide and decides whether to pursue it.

The fastest route is the online form at irs.gov/compliance, where you can describe what you observed without creating a paper trail. If you prefer to mail a report, you can send Form 3949-A to the IRS office that serves your area. You can also call the IRS Criminal Investigation Hotline at 1-800-366-4484 to report by phone, though you will need to provide basic details about the person and the suspected violation.

Reports can be made anonymously, though providing your contact information helps the IRS follow up if investigators need clarification. The IRS does not disclose the identity of people who report fraud, and retaliation for reporting is illegal under federal law.

Key Takeaways

  • The IRS accepts fraud reports online at irs.gov/compliance, by mail using Form 3949-A, or by phone at 1-800-366-4484.
  • You can report anonymously, and the IRS will not disclose your identity to the person you report.
  • Provide specific details about the suspected fraud — what income was hidden, what deductions were false, or what documents were forged — rather than general accusations.
  • The IRS investigates reports based on the information you give; you do not need proof or certainty before reporting.
  • If you are a whistleblower with inside knowledge of large-scale fraud, you may be may have access to to a financial award under the IRS Whistleblower Program.

What information to include in your report

The IRS needs specific details to investigate. Include the person's name, address, phone number, and Social Security number or employer identification number if you have it. Describe what you observed: unreported cash income, false business deductions, inflated charitable donations, offshore accounts, or employees paid under the table. If you know the tax years involved, include those.

Explain how you know this information — did you work for the person, see their tax documents, or observe their business practices directly? The more concrete your description, the more likely the IRS can act. Vague accusations like "I think they cheat" do not give investigators enough to work with. Instead, say something like "I worked as a bookkeeper for their business in 2022 and saw them record personal expenses as business deductions" or "I saw cash payments to workers that were never reported on payroll."

If you have documents — receipts, emails, bank statements, or copies of filed returns — you can attach them or describe where the IRS might find them. You do not have to provide originals; copies or descriptions are sufficient to start an investigation.

The IRS Whistleblower Program and financial awards

If you have inside knowledge of tax fraud involving more than $2 million in taxes owed (or $2 million in gross income if taxes are hard to calculate), you may be may have access to to a financial award under the IRS Whistleblower Program. Awards range from 15 to 30 percent of the taxes, penalties, and interest the IRS collects as a result of your report.

To pursue a whistleblower award, you must file Form 211 (process for Award for Original Information) with the IRS Criminal Investigation division. Unlike a standard fraud report, a whistleblower claim requires you to provide your identity and detailed information about the fraud. The IRS will not award money based on anonymous tips or public information already known to the government.

The process is slow — investigations can take years, and the IRS only pays awards after it collects the money from the person who owes it. You should not report fraud expecting a quick payout. If you have evidence of large-scale fraud and are willing to be identified, consult a tax attorney or whistleblower attorney before filing; they can advise whether your case meets the threshold and help you present your information effectively.

What happens after you report

After you submit a report, the IRS Criminal Investigation division reviews it to decide whether to open an investigation. This can take weeks or months. You will not receive updates on the status unless you filed as a whistleblower with Form 211, in which case the IRS may contact you for additional information.

If the IRS decides to investigate, agents may contact the person you reported, examine their tax returns and financial records, and interview witnesses. Criminal investigations can result in civil penalties (additional taxes and interest), civil fraud penalties (75 percent of the underpaid tax), or criminal prosecution (fines and imprisonment). Not all reports lead to prosecution — the IRS prioritizes cases involving large amounts of money or egregious conduct.

You will not be told the outcome of the investigation. The IRS does not notify reporters when a case closes or what action was taken, both to protect your privacy and to avoid tipping off the person under investigation.

Reporting fraud by a business or employer

If you suspect a business is committing tax fraud — hiding income, falsifying payroll records, or claiming false deductions — you can report it the same way you would report an individual. Include the business name, address, employer identification number (EIN), and the names of owners or managers if you know them.

Describe the specific fraud: Are employees paid in cash and not reported on W-2 forms? Are personal expenses run through the business? Is income from a side business not reported on the tax return? If you worked there or have access to payroll or accounting records, say so. The IRS uses this context to evaluate whether the report is credible.

If you are a current or former employee reporting your employer, you have additional protections under whistleblower laws. Retaliation — firing, demotion, harassment, or threats — is illegal. If you face retaliation after reporting, you can file a complaint with the Occupational Safety and Health Administration (OSHA) or consult an employment attorney.

When to report to other agencies instead

Tax fraud sometimes overlaps with other crimes. If you suspect money laundering, wire fraud, identity theft, or other federal crimes, you can also report to the Federal Bureau of Investigation (FBI) at tips.fbi.gov or call 1-800-CALL-FBI. If the fraud involves a financial institution, the Financial Crimes Enforcement Network (FinCEN) accepts reports at FinCEN.gov.

State tax agencies also investigate state income tax fraud. If you suspect someone has evaded state taxes, contact your state's department of revenue or tax authority. Some states offer their own whistleblower programs with financial awards.

You do not have to choose one agency — you can report to the IRS and the FBI simultaneously if the conduct involves both tax evasion and other federal crimes. Each agency will investigate within its jurisdiction.

Protecting yourself when reporting

If you are reporting someone you know — a family member, friend, or colleague — be aware that the investigation may become public, especially if it leads to criminal charges. The person may eventually learn who reported them, though the IRS keeps your identity confidential during the investigation.

If you work for the person you are reporting, consider whether reporting could affect your job security. While retaliation is illegal, proving it can be difficult. Some people consult an employment attorney before reporting their employer to understand their rights and protections.

Do not attempt to gather evidence by accessing someone else's financial records, emails, or tax documents without permission. Doing so could expose you to civil or criminal liability. Report only what you have observed directly or what you have a legitimate right to know.

Frequently Asked Questions

Can I report someone anonymously?

Yes. You can submit a report online or by mail without providing your name or contact information. The IRS will not disclose your identity to the person you report. However, if you want to pursue a whistleblower award, you must identify yourself on Form 211.

What if I'm not sure whether what I saw was actually fraud?

Report it anyway. The IRS investigates based on the information you provide and determines whether fraud occurred. You do not need certainty or proof — describe what you observed and let investigators decide whether it warrants further action.

How long does it take for the IRS to investigate?

Criminal investigations can take months or years. You will not receive updates unless you filed as a whistleblower. The IRS does not notify reporters of outcomes to protect privacy and avoid alerting the person under investigation.

What if the person I report is a friend or family member?

The IRS treats all reports the same way regardless of your relationship. If you are concerned about the personal consequences, consult a trusted advisor or attorney before reporting. Retaliation for reporting is illegal, but it can still happen informally.

Can I get money for reporting tax fraud?

Only if the fraud involves more than $2 million in taxes owed and you file Form 211 as a whistleblower. Awards range from 15 to 30 percent of what the IRS collects, but the process takes years and payment only happens after the IRS collects the money.