Gather evidence of the suspected fraud
Identify the person or business involved
Determine the tax authority to contact
Use the official fraud reporting form or hotline
Submit the report online, by mail, or by phone as instructed
Include names, addresses, dates, amounts, and supporting documents
Provide your contact information if you want follow-up
Request confidentiality or anonymity if available
Keep copies of everything you submit
Follow up if the tax authority requests more information