This program will help you write a demand letter asking your landlord to return a security deposit. Here's everything you need to know about not returning security deposits, including a security deposit refund letter template.Learn the basics of how to write a security deposit letter to a tenant. 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. Your computer must have the Adobe Acrobat Reader installed in order to view any of these documents. The letter should state whether the deposit is being returned in full, partially returned, or not returned at all. Please note, if a refund is approved, it will be forwarded to the person receipted. Please allow 4 to 6 weeks for request to be processed.