A credit dispute letter is a formal document that businesses send to credit bureaus to rectify inaccuracies or outdated information in their credit reports. 1. In the sample letter, fill in your personal information.This sample letter explaining credit problems will help you focus your efforts when appealing to a property manager for an apartment. A 609 dispute letter is a formal request sent to credit bureaus to verify the accuracy of the information on your credit report. Use this sample letter to dispute mistakes on your credit report. The following are common reasons you may be required to provide a letter of explanation. Late or missing payments. Example: Selena falls behind on her credit card payments, and after several months of missed payments, the card company marks the account as a charge-off. One way to fix an error on your credit report is to write a credit dispute letter and mail it to one or more credit bureaus. You may owe a debt, but you still have rights.