​​​See How Do You Report Suspected Tax Fraud Activity? for current information.

If you suspect or know of an individual or business that you believe may be planning to file an incorrect income tax return this filing season, you may report this information to the Department of Revenue. Reportable activity may include concerns about a client's eligibility for the Homestead Credit or Earned Income Credit, or documentation presented by clients that you suspect may be false or incorrect. The department has the ability to flag a taxpayer's account so that any return filed by that taxpayer can be reviewed prior to processing the return.

You may report suspected fraud on Form P-626 located on the Department of Revenue's website at www.Revenue.wi.gov. Complete Form P–626 online, print the form and mail or fax it to:

Wisconsin Department of Revenue
Audit Bureau, Unit E
Mail Stop 5–144
PO Box 8906
Madison, WI 53708–8906
Fax: (608) 221–6637

If you have questions, call (608) 266-6639. Practitioners may also call the practitioner phone number that was previously sent by email through the practitioner list serv.

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 incorrect returns. Information provided should include full name, social security number, address and a brief explanation of the suspected problem.

Although you are not required to identify yourself, it is helpful if you do so in the event we need to contact you for clarification or additional information. Your identity can be kept confidential. The Wisconsin Department of Revenue does not offer rewards for reporting tax fraud.

Privacy and disclosure laws prohibit the Department of Revenue from sharing information on any action taken based on the information you provide.

January 2, 2014