How Do You Report Suspected Tax Fraud Activity?

The Wisconsin Department of Revenue is protecting taxpayers using strong fraud protection safeguards. Those protection efforts include relying on tips from the public to help identify potential tax fraud. If you suspect an individual or business is not complying with the tax laws, you may report this information anonymously to us.

Online referral form
Report suspected fraud by completing Form P-626, Wisconsin Tax Information Referral Form. You may email, mail, or fax the form to us.

When reporting any type of suspicious activity, please provide as much information as possible to assist us in properly identifying the taxpayer and any potential fraudulent activity. Examples include: the name and address of the suspect, why you think tax fraud is being committed, how much money is involved, any personal or financial information you have concerning the suspect, etc.


Use the button on the upper right corner of the form or email:

Mail to:

Wisconsin Department of Revenue
Audit Bureau
Mail Stop 5-144
PO Box 8906
Madison, WI 53708-8906

FAX to:

(608) 221-6637

Questions: (608) 266-2772.

Your identity can be kept confidential. However, it helps if you provide your contact information in case we have questions about the information you submitted. Under state privacy laws, we can't disclose what, if any, action we take based on information you provide. We do not offer rewards for reporting this information.

Additional Resources
Learn more about our Protecting Taxpayer efforts.

If you are a tax professional who has experienced a data breach or theft of information which could potentially result in fraudulent refund activity, please contact the IRS for assistance at

November 24, 2017