This sample letter explaining credit problems will help you focus your efforts when appealing to a property manager for an apartment. 1. In the sample letter, fill in your personal information.Our guide will teach you how to write a letter of explanation, plus offers a free template to help you write one of your own. Use this sample letter to dispute mistakes on your credit report. When you write a goodwill letter, you're asking a creditor or collection agency to remove a negative mark on your credit reports. Providing a letter that explains your credit can help if you have a low credit score. Use this sample letter to get your next apartment.