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.This guide will help landlords navigate the rental application denial process and provide a free rental application denial letter template. First, clearly state the reason for the appeal of the property's decision and restate their reason for denying your rental application. Good evening, BP. I'm writing my Tenant Rejection Letter and found some reasons online as to why a tenant is denied their application. The best time to send an appeal letter is within a week from receiving the denial letter.