Create a compelling demand letter for your security deposit in New York. Learn essential components, legal tips, and get a free template.We've included a sample letter to return security deposit funds for a full refund, partial refund, and no refund. Here's everything you need to know about not returning security deposits, including a security deposit refund letter template. You are now over a week late returning my deposit. The letter should state whether the deposit is being returned in full, partially returned, or not returned at all. What does a security deposit request letter include? It documents the amount of the security deposit that is being refunded. This part of the security deposit letter refers to the original lease, its effective date, the tenant's move-out date, and the security deposit amount. 1. Enter the date and lease termination details.