Your letter should have a professional and informative tone, covering exactly why you're denying their rental application. Download a customizable rental application rejection letter template for landlords or property managers to professionally notify applicants.In the letter, express your appreciation for the applicant's interest and politely explain why you declined them. This guide will help landlords navigate the rental application denial process and provide a free rental application denial letter template. Why don't you want to go into details of why they are denied? You can ask, but they don't have to answer. They also don't have to be truthful, as admitting to discrimination of any kind is admission of an illegal action. First, clearly state the reason for the appeal of the property's decision and restate their reason for denying your rental application. A landlord may ask you to fill out a rental application. The best time to send an appeal letter is within a week from receiving the denial letter.