When you send a debt validation letter to a collection agency, they are required to honor your request and provide proof that the debt really belongs to you. Otherwise, you might get stuck paying someone else’s bill. You would be amazed at the different errors that are made on people’s credit reports. Things such as the misspelling of their first or last name. This mix up can add thousands of dollars of debt to your credit that belongs to someone else. So, it is good to take advantage of the opportunity to dispute a debt. And, do it fast. delay will make it harder for you to get a response.