How To Write A Letter To Inform Of Fraud . This information should be as specific as possible, to give the respondent a genuine opportunity to respond to the allegations. This may include receipts, warranties, cheques, pictures, videos if there are any. Letter to Notify the IRS of a Fraudulent Tax Filing (Template With Sample) from www.rocketlawyer.com Mention authority you approached to voice about it. (a) put your name, address, and telephone number (s) at the top left of the page. Give a brief history of your efforts to resolve the problem, if the information helps explain why you’re writing to the company.