Fill out Form 3949-A Online in 2026

Individuals use Form 3949-A to report suspected tax law violations to the Internal Revenue Service. It allows you to provide information about a person or business that may be involved in activities such as unreported income, false deductions, or other forms of tax fraud.

Submitting this form helps the IRS review potential noncompliance and take appropriate action to protect the integrity of the tax system. It is intended for anyone who has credible information about possible tax evasion or related violations and wants to alert the IRS so that tax laws are applied fairly and consistently.

Use Form 3949-A to report suspected tax law violations to the Internal Revenue Service. It allows individuals to notify the IRS of potential noncompliance by a person or business in a clear, structured way.

Common use cases include:

• Unreported income, including cash or off-the-books payments
• False exemptions or deductions, such as improperly claiming dependents or tax credits
• Other tax violations, including kickbacks, false documents, or failure to file a tax return

Section A – Information About the Person or Business You Are Reporting

• Lines 1a–k (Individual) Use these lines if you are reporting a person. Provide identifying and contact details if known. Leave any unknown fields blank.
• Lines 2a–i (Business) Use these lines if you are reporting a business. Enter business identification and contact details if available. If you are reporting both a business and its owner, complete both Line 1 and Line 2.

Section B – Describe the Alleged Violation of Income Tax Law

• Line 3 Indicate the type of tax violation you believe occurred by selecting all applicable options.
• Line 4 List the tax years involved and estimated amounts for any unreported income, if known.
• Line 5 Briefly explain the situation, including what happened and how you became aware of it. Add an extra page if needed.
• Line 6 Provide additional context if available, such as whether records exist, potential safety concerns, or financial institutions involved.

Section C – Information About Yourself (Optional)

• Line 7a–g Provide your contact information only if you are willing to be contacted for follow-up. This section is optional and confidential.

Form 3949-An is completed by individuals who want to report suspected tax law violations to the IRS. After submission, the IRS reviews the information and determines whether further action or investigation is appropriate.

Form 3949-An is not required when the issue being reported does not qualify as a reportable tax law violation or when the IRS requires a different form for that situation.

For example, it should not be used to report identity theft, tax preparer misconduct, abusive tax schemes, or issues involving tax-exempt organizations, as each of these has a separate IRS reporting process. In such cases, submitting Form 3949-A would not be appropriate.

Form 3949-A does not have a specific due date. It may be submitted at any time after you become aware of a suspected tax law violation.

While there is no filing deadline, submitting the form as soon as reasonably possible helps ensure the information is timely and useful for the IRS's review.

To get a blank Form 3949-An issued by the Internal Revenue Service, you can use our platform, where the form template is already available in an online editor. There's no need to download the form separately from the IRS website.

You can fill out Form 3949-A directly on our site and download the completed version when you're finished. Please note that while we help you prepare and download the form, submission to the IRS must be done on your own.

Form 3949-A does not require a signature. According to IRS instructions, you can submit the form without signing it, and you may also choose to file it anonymously. Providing your name or contact details is optional and only used if the IRS needs additional information.

As with any IRS form, it's a good idea to review the most current instructions to make sure no requirements have changed.

You can file a 3949-A Form in two ways: online through the IRS Form 3949-An Information Referral experience, or by printing and mailing the completed form to the address listed in the official instructions (currently PO Box 3801, Ogden, UT 84409).

• Form 211 – Application for Award for Original Information Used when you want to seek a whistleblower reward based on the information you provide. This form often complements Form 3949-A but serves a different purpose.
• Form 14039 – Identity Theft Affidavit Used instead of Form 3949-A when the issue involves identity theft or misuse of personal information.
• Form 14157 – Return Preparer Complaint Used to report misconduct by a tax return preparer, which should not be reported on Form 3949-A.
• Form 14157-A – Tax Return Preparer Fraud or Misconduct Affidavit Use this form when a tax return preparer has filed a return or altered your tax data without authorization. It is typically submitted alongside Form 14157 and is required when the preparer's fraud directly affects your tax return.
• Form 14242 – Report Suspected Abusive Tax Promotions or Preparers Used to report abusive tax avoidance schemes or promoters, rather than general tax violations.