1. In the sample letter, fill in your personal information. Your letter should also include copies of important documents to help the bureaus conduct an investigation.A credit dispute letter is a formal document that businesses send to credit bureaus to rectify inaccuracies or outdated information in their credit reports. For example, the letter should contain their full name, contact information, and a clear explanation of what information they are disputing. I respectfully request that your offices provide me with competent evidence that I have any legal obligation to pay you. State Your Request: In the opening paragraph, clearly state your request for debt validation. Use formal language and be specific about what you are requesting. Learn how to write an effective collection dispute letter with our guide and templates. The actual letter of credit for rent should be as transparent as possible. Stick to the facts, and don't hide any information.