IRS Form 3949-A: How to Report Suspected Tax Fraud

The IRS estimates the gross tax gap for tax year 2022 at $696 billion. That number sounds massive because it is, but it needs context. The tax gap includes taxes that were not paid on time because of nonfiling, underreported income, and underpayment. It does not mean every unpaid dollar came from criminal fraud.

Still, the gap shows why the IRS gives taxpayers a way to report suspected tax law violations. IRS Form 3949-A is one of those tools.

Use it carefully. This form is not for every tax complaint, every bad preparer situation, or every identity theft problem. It is for reporting alleged federal tax law violations by a person, business, or both, especially when you have specific facts the IRS can review.

That distinction matters.

Key takeaways about IRS Form 3949-A

IRS Form 3949-A, Information Referral, is used to report alleged tax law violations by an individual, business, or both.
You can use it for issues such as unreported income, false deductions, failure to file, false documents, kickbacks, or failure to pay or withhold taxes.
The IRS now allows Form 3949-A to be submitted online through its Form 3949-A Information Referral online experience.
Do not use Form 3949-A for identity theft, tax preparer misconduct, abusive tax schemes, or tax-exempt organization complaints. The IRS has separate forms for those situations, and using the wrong one can send you down the wrong path.
A stronger report includes names, dates, tax years, dollar amounts, how you learned about the issue, and supporting documents when you have them legally.
The IRS usually does not send updates after you submit the form. You provide the information, then the IRS decides what to do with it.

What is IRS Form 3949-A?

IRS Form 3949-A, Information Referral, is the IRS form used to report suspected federal tax law violations by a person or business. The IRS form instructions list examples such as unreported income, false deductions, false documents, failure to file, failure to pay tax, and failure to withhold tax.

Here is what that means in plain English: you use this form when you believe someone may be violating federal tax rules and you have facts that support the concern.

It is not the form for fixing your own tax return. It is not the form for checking a delayed refund. It is not the form for reporting that someone stole your identity and filed a return under your name.

Different IRS problems have different reporting paths. Form 3949-A is an information referral. You give the IRS the details, and the IRS decides whether the information supports further review.

When should you use IRS Form 3949-A?

You should use IRS Form 3949-A when you have specific, credible information about a possible federal tax law violation by a person or business. The key word is specific. The IRS needs enough detail to understand who is involved, what happened, which tax years may be affected, and why the information may point to a tax issue. The IRS fraud reporting page also points taxpayers toward reporting specific tax violations through the right channel. Form 3949-A may apply to issues such as:

Unreported income
False deductions or exemptions
False or altered tax documents
Failure to file a required tax return
Failure to pay tax
Failure to withhold tax
Kickbacks
Multiple tax return filings
Earned Income Tax Credit violations
Illegal wagering or gambling income
Public or political corruption tied to tax issues

A stronger report sounds factual, not emotional.

For example, “this business receives cash payments and does not report them” is more useful if you can explain how you know, what years are involved, and what records may support the claim. Maybe invoices exist. Maybe payroll records show something different from what the owner reported. Maybe the person told workers they would be paid “off the books.”

That kind of detail helps.

A report that only says “I think this person is cheating on taxes” is weaker. It may be true, but the IRS needs more than suspicion.

When should you not use IRS Form 3949-A?

Do not use IRS Form 3949-A when the IRS has a more specific form for your situation. This is one of the easiest places to make a mistake. You may know something is wrong, but the IRS still needs the information sent through the right channel. The Form 3949-A instructions direct taxpayers to other forms for several situations.

Here is the practical breakdown:

Situation	Better IRS form or process
Someone used your Social Security number or filed a return using your identity	Form 14039, Identity Theft Affidavit
A tax preparer acted improperly	Form 14157, Return Preparer Complaint
A preparer filed or changed your return without your consent	Form 14157-A
You want to report an abusive tax scheme or promoter	Form 14242
You want to report a tax-exempt organization	Form 13909
You want to claim a whistleblower award	Form 211
You received a fake IRS email, text, call, or message	IRS scam reporting process

This is where form choice matters.

If someone used your dependent or Social Security number, that points toward the IRS identity theft process. If a preparer filed a return without your approval, the preparer complaint forms are usually the better fit. If someone is selling a tax avoidance program that sounds too good to be true, the abusive tax scheme process may be the right place to start.

Use Form 3949-A when the main issue is an alleged federal tax law violation by a person or business, and no more specific IRS reporting form fits better.

What information should you include on IRS Form 3949-A?

A stronger Form 3949-A report gives the IRS enough detail to understand who is being reported, what happened, when it happened, and why the information may matter.

The IRS Internal Revenue Manual explains that useful referral information may include the taxpayer being reported, the type of activity, how the information became known, when the alleged violation happened, and the amount involved.

Before you submit the form, gather what you know:

Name of the person or business
Address, phone number, email, or website, if known
Social Security number, taxpayer identification number, or employer identification number, if known
Tax years involved
Type of suspected violation
Estimated dollar amount
How you learned about the issue
Whether books, invoices, payroll records, bank statements, or other documents may exist
Copies of supporting documents, if you have them legally
Your contact information, if you choose to provide it

Do not guess just to fill every box.

If you do not know the person’s SSN or EIN, leave it out or explain what you do know. A report with clear facts and a missing ID number can still be useful. A report packed with guesses can create confusion.

Also, keep your language clean and direct. You do not need to sound dramatic. You need to be accurate.

How do you submit IRS Form 3949-A?

You can now submit IRS Form 3949-A online through the IRS Form 3949-A Information Referral online experience. The IRS lists online submission as a recent development on its Form 3949-A page.

The IRS also announced a newer Submit a Tip tool for suspected tax fraud, scams, evasion, and other tax-related illegal activity. The IRS says the tool uses prompts to help route information to the right IRS office.

Here is the basic process:

Confirm Form 3949-A is the right form.
Before you start, make sure the issue does not belong on Form 14039, Form 14157, Form 14242, Form 13909, or Form 211.
Write down the facts first.
List the names, dates, tax years, estimated amounts, and documents before you begin the online form.
Use the IRS online reporting option.
Complete the Form 3949-A Information Referral online experience through IRS.gov.
Answer each question carefully.
Use plain language. Explain what happened and how you know.
Include supporting information when you have it.
If you have records, describe or attach them as allowed. If you do not have records but know where they may exist, say that.
Keep your own copy.
Save a copy or written summary of what you submitted.

You can still use the paper form if needed. If you do, follow the instructions on the IRS form and mail it to the address listed there.

For most people, the online option is now the cleaner path. It also makes the old “print and mail” workflow feel outdated as the main instruction.

What happens after you submit Form 3949-A?

After you submit Form 3949-A, the IRS reviews the referral to decide whether the information describes a possible tax law violation.

That does not mean the IRS will automatically open an audit. It does not mean the person or business will be contacted right away. Some reports do not include enough detail. Others may contain useful facts that the IRS can compare against tax records, filing history, or other information.

The strongest referrals usually answer these questions:

Who is being reported?
What allegedly happened?
When did it happen?
Which tax years are involved?
How did you learn about it?
What amount of money is involved?
What documents support the allegation?

The IRS generally does not tell you what happens next. That can feel frustrating, but tax information is private. The IRS cannot disclose another person’s return, account activity, or enforcement status to you.

So your role is limited: submit clear, truthful information and keep your own record. Then the IRS takes it from there.

Is IRS Form 3949-A anonymous?

The IRS allows people to report tax-related information in several ways, including anonymously. The IRS whistleblower claim page also says you can report information anonymously without filing a whistleblower claim for an award.

Still, anonymous reporting has trade-offs.

If you include your contact information, the IRS may be able to follow up if something is unclear. If you stay anonymous, you protect your identity in the submission, but you also limit the IRS’s ability to ask questions.

Neither option is perfect for every situation.

If the matter is sensitive, think carefully before including your name. If the facts are complicated and you are comfortable being contacted, providing contact information may make the referral easier to evaluate.

IRS Form 3949-A vs Form 211: what is the difference?

IRS Form 3949-A reports alleged tax law violations. IRS Form 211 is used to submit a whistleblower claim for an award.

Those two forms serve different purposes.

The IRS Whistleblower Office says award amounts generally range from 15% to 30% of collected proceeds attributable to the whistleblower’s information, when the claim qualifies.

Issue	Form 3949-A	Form 211
Main purpose	Report suspected tax law violations	Claim a whistleblower award
Best for	General information referrals	Award claims based on specific information
Anonymous option	Can be submitted without identifying yourself	Award claims require identifying information
IRS updates	Usually no updates	The whistleblower process has separate claim procedures
Main risk	Using the wrong form or giving vague facts	Filing an award claim without meeting requirements

If you only want to report suspected tax fraud, Form 3949-A may be the right fit.
If you want to request a monetary award, review the Form 211 process carefully. Do not assume every report qualifies for an award. Many do not.

What mistakes should you avoid when reporting suspected tax fraud?

The biggest mistake is using Form 3949-A as a catch-all complaint form. It is more specific than that.

Avoid these common problems:

Using Form 3949-A for identity theft
Using it for tax preparer misconduct when Form 14157 is more appropriate
Sending a vague accusation with no dates, names, or facts
Guessing at dollar amounts without saying they are estimates
Sending documents you obtained improperly
Reporting a personal disagreement as tax fraud
Expecting the IRS to send status updates
Using harsh or emotional wording instead of clear facts
Confusing a tax mistake with intentional tax fraud

That last point deserves a closer look.

A wrong tax return is not automatically fraud. A business owner may have messy books. A taxpayer may misunderstand a credit. A payroll issue may come from poor records rather than intentional conduct.

The IRS can evaluate the facts. Your job is to report what you know, not to prove the entire case yourself.

What if the tax issue involves your own return?

Do not use IRS Form 3949-A to fix your own return.

If your tax return has missing income, incorrect deductions, wrong credits, or a filing mistake, you may need to review your return, check your IRS records, or file an amended return. That is a different problem.

This is where a tax transcript can help. A transcript can show wage and income records, account activity, return processing, and certain IRS adjustments.

If you received a notice, slow down before responding. Read the letter. Check the tax year. Look at the deadline. Then compare the IRS claim to your actual records.

Filing quickly matters. Filing accurately matters more when the IRS is already questioning income, withholding, credits, or balances.

How H&S Accounting & Tax Services can help with related IRS issues

H&S Accounting & Tax Services does not need to be involved every time someone submits Form 3949-A. Many taxpayers can report clear, factual information directly through the IRS online process.

Where professional help may matter is when the problem affects your own tax records.

You may need help if:

You received an IRS notice
Your refund is delayed because income or withholding does not match IRS records
Someone used your dependent or filing information
A preparer filed something you did not approve
Your business books do not support the numbers on your tax return
You need to review a transcript before responding to the IRS

H&S Accounting & Tax Services provides IRS notice review, tax problem diagnosis, transcript review, IRS correspondence, and IRS help when authorized and properly scoped. The firm also provides income tax preparation and tax document review for individuals and small business owners.

If your issue is about your own IRS notice or tax filing, start with IRS help or schedule an appointment. If the issue is identity theft, the IRS identity theft process may be the better first step. You can also review the IP PIN guide if your identity or filing information may be at risk.

FAQ about IRS Form 3949-A

Can I submit Form 3949-A online?

Yes. The IRS now allows Form 3949-A to be submitted online through its Form 3949-A Information Referral online experience. The IRS also has a Submit a Tip tool that helps route suspected tax fraud, scams, evasion, and other tax-related illegal activity.

Is Form 3949-A anonymous?

You can report information anonymously, but anonymous reporting has limits. If you do not provide contact information, the IRS may not be able to ask follow-up questions. If you do provide contact information, the IRS may have a better way to clarify details.

What information makes a Form 3949-A report stronger?

Specific facts make the report stronger. Include the person or business name, tax years, estimated dollar amount, what happened, how you learned about it, and any documents that support the allegation. If something is an estimate, say so.

Is IRS Form 3949-A the same as Form 211?

No. Form 3949-A is for reporting alleged tax law violations. Form 211 is for submitting a whistleblower claim for an award. If you want to request a whistleblower award, review the IRS Form 211 process instead of assuming Form 3949-A is enough.

Can I use Form 3949-A for identity theft?

No. The IRS instructions say not to use Form 3949-A if you suspect identity theft. Use Form 14039, Identity Theft Affidavit, for that type of problem.

Will the IRS tell me what happened after I submit Form 3949-A?

Usually, no. The IRS may review the information, but it generally does not disclose the outcome to the person who submitted the referral. Tax information is private, so you should not expect status updates about another person’s or business’s IRS account.

Final thoughts

IRS Form 3949-A is useful when you have specific, credible information about suspected tax law violations by a person or business. The form now has an online submission option, so taxpayers no longer need to think of it as only a paper-and-mail process.

Use the right form. Stick to facts. Include names, dates, tax years, amounts, and documents when you have them.

If the issue involves your own return, refund, IRS notice, identity, or tax records, do not rush into the wrong reporting path. Review your IRS records first. Correct your own filing if needed. And if the issue is already tied to an IRS notice or unresolved tax problem, get the right help before you respond.