In this article, readers will find a comprehensive example collection letter sample designed to maximize response rates and ensure clarity. The Illinois Department of Revenue (IDOR) sends letters and notices to request additional information and support for information you report on your tax return.Use this letter to ask a customer to pay the money that they owe you. Put your business letterhead at the top of the letter. The Accounts Receivable and Cost Recovery Division is responsible for the collection of a variety of City receivables including ambulance bills. A demand letter typically includes specific details about the debt, such as the invoice number, the amount owed, and the due date. Overpayments. To receive important letters about overpayment recovery waivers, please ensure your mailing address is updated in your IDES account. Claiming a Property. Rule Tax and General Fee collections and revenue recovery operations. Forms should be downloaded to your computer before filling in the fields.