The letter should state whether the deposit is being returned in full, partially returned, or not returned at all. You are now over a week late returning my deposit.Security Deposit Demand Letter – For a tenant requesting to get back their security deposit. Sample. Download: PDF, MS Word, ODT. Here's everything you need to know about not returning security deposits, including a security deposit refund letter template. We've included a sample letter to return security deposit funds for a full refund, partial refund, and no refund. The demand letter states that the landlord is in violation of state law and must return the deposit or face legal action. Learn the basics of how to write a security deposit letter to a tenant. It documents the amount of the security deposit that is being refunded. In the next section, we will discuss some things a landlord can count as deductions from the security deposit.