To report someone for not filing taxes, submit IRS Form 3949-A, the agency’s Information Referral. You can fill it out online or print and mail it to Internal Revenue Service, PO Box 3801, Ogden, UT 84409.1Internal Revenue Service. About Form 3949-A, Information Referral You can file anonymously. If you want to be eligible for a cash award, you have to use a different form and give up the anonymity.
Filing Form 3949-A
Form 3949-A is the IRS’s general-purpose tip form. It covers failure to file, unreported income, false deductions, failure to withhold, and organized crime, among other categories.2Internal Revenue Service. Report Tax Fraud, a Scam or Law Violation Identity theft and tax preparer fraud use different IRS channels.
When you fill out the form, include whatever you know about:
- The person’s or business’s full name, address, Social Security number or taxpayer identification number, date of birth, and occupation.
- The tax years you believe were skipped or underreported.
- A description of what you believe happened and how you learned about it.
- Any supporting documents, financial records, or other evidence.
You don’t need every field filled in. The IRS instructions say to leave blank anything you can’t answer.3IRS. Form 3949-A (Rev. 10-2020) Information Referral But a vague tip without identifying details is unlikely to go anywhere. A name, an approximate income range, and a specific description of the violation give the agency something it can actually act on.
Anonymous Tip or Whistleblower Claim?
You have two separate paths, and the choice matters.
Form 3949-A is the anonymous route. You are not required to identify yourself, and the IRS accepts the tip either way.2Internal Revenue Service. Report Tax Fraud, a Scam or Law Violation You will not hear anything back, and you cannot receive an award.
Form 211, “Application for Award for Original Information,” is the whistleblower route. It goes to the IRS Whistleblower Office, and you must identify yourself, give contact information, and sign under penalty of perjury.4Internal Revenue Service. Form 211 – Whistleblower Office5Internal Revenue Service. Submit a Whistleblower Claim for Award Anonymous tips are not eligible for awards.
If the taxes, penalties, and interest in dispute exceed $2 million, or if the reported person’s gross income tops $200,000 in any year at issue, the award is mandatory: 15% to 30% of what the IRS collects, with the exact percentage depending on how much your information contributed.6Office of the Law Revision Counsel. 26 USC 7623 – Expenses of Detection of Underpayments and Fraud, Etc. On a $3 million collection, that’s between $450,000 and $900,000. Below those thresholds, the IRS can still pay an award, but it’s discretionary and tends to be smaller and less predictable.
Department of Treasury employees cannot collect awards, and no award can be paid on information that wasn’t submitted under penalty of perjury.6Office of the Law Revision Counsel. 26 USC 7623 – Expenses of Detection of Underpayments and Fraud, Etc.
What You’ll Hear Back
If you filed a general referral on Form 3949-A, you will hear nothing. Federal law bars the IRS from disclosing taxpayer return information, so the agency cannot tell you whether it opened a case, what it found, or how it ended.7Office of the Law Revision Counsel. 26 USC 6103 – Confidentiality and Disclosure of Returns and Return Information The tip goes in and stays in.
Form 211 whistleblowers get different treatment. The same confidentiality statute carves out disclosure rights for them. The IRS must notify you within 60 days after your case is referred for audit, and again within 60 days after the taxpayer makes a payment related to your information. You can also submit written requests for status updates and, if an award is decided, the reasoning behind it.7Office of the Law Revision Counsel. 26 USC 6103 – Confidentiality and Disclosure of Returns and Return Information
Either way, the IRS screens incoming referrals and prioritizes based on how credible the allegations look and how much revenue is realistically at stake. Not every tip becomes an investigation.
If the Person You’re Reporting Is Your Employer
Federal law protects employees who report tax violations. An employer cannot fire, demote, suspend, threaten, or harass you for reporting to the IRS, the Department of Justice, Congress, or an internal supervisor with authority to investigate the misconduct. The protection also covers employees who testify or participate in an IRS enforcement action.6Office of the Law Revision Counsel. 26 USC 7623 – Expenses of Detection of Underpayments and Fraud, Etc.
If retaliation happens anyway, you can file a complaint with OSHA, which investigates these claims. If OSHA finds in your favor and the matter doesn’t settle, the agency can order reinstatement, double back pay, and restoration of benefits. The IRS also protects whistleblower identities to the extent the law allows; identity disclosure to the reported taxpayer is rare and usually only happens if you become an essential witness in court.5Internal Revenue Service. Submit a Whistleblower Claim for Award
Think Twice Before Reporting Out of Spite
The referral process is not consequence-free for the person submitting it. Knowingly making a false statement to a federal agency is a crime, punishable by up to five years in prison and a fine.8Office of the Law Revision Counsel. 18 U.S. Code 1001 – Statements or Entries Generally That applies to materially false information you deliberately put on a Form 3949-A or Form 211.
On the civil side, someone who willfully files a fraudulent information return about another person can be sued. The target of a false filing can recover the greater of $5,000 or their actual damages, plus court costs and potentially attorney fees, and they have six years from the fraudulent filing to bring the suit.9Office of the Law Revision Counsel. 26 U.S. Code 7434 – Civil Damages for Fraudulent Filing of Information Returns File only if you have a genuine, good-faith basis for believing someone isn’t meeting their tax obligations.
State Taxes Are Separate
Form 3949-A covers federal taxes only. If someone isn’t filing state returns, you need to contact that state’s department of revenue or taxation separately. Most states run their own fraud reporting systems, and many accept anonymous tips the way the IRS does, but the forms and procedures vary by state. Check your state revenue department’s website for the specifics. State penalties are assessed independently of anything the IRS does.