Unfortunately, many credit reports contain errors. One common type of credit report error is the mixed file. A "mixed file" is a term used to describe a credit report when credit information for one person is placed on the credit report of another person, creating a false description of the person's credit history. Occasionally, this problem is caused by the "furnisher" of credit information (ie. a bank or credit card company). For example, a bank may incorrectly report that a spouse is responsible for a mortgage loan that was only in his wife's name.
More often, a mixed file is caused by the way credit reporting agencies match data to a consumer's file to create his credit report. Credit reporting agencies get mountains of credit data from creditors and public records. This data is then matched to an individual consumer's credit report through identifying information such as name, address, and social security number. Mixed files occur when the credit reporting agency's computer doesn't correctly match the identifying information in the credit data to the identifying information in the credit report. The credit reporting agencies closely guard their exact matching criteria and process, but it appears that commons reasons for mixed files include:
Mismatches between generations with the same name (ie. Jr./Sr.)
People with similar names (ie. Jon Smith / Jonathan Smith)
People with similar social security numbers
Mixed files are a big problem. According to one study, 44% of consumer complaints to the FTC involved mixed files. It's a particularly serious problem with the other person's accounts are delinquent or in collections. This can torpedo your credit score and lead to debt collection calls for a debt you don't owe. And mixed files are often very difficult to fix because it can be difficult to prove a negative--that the account isn't yours. You may have to submit birth certificates, social security cards, or sworn statements in order to prove an account doesn't belong to you.
If your credit report appears to have been mixed with someone else's, the first step is to write a detailed dispute letter to the credit reporting agency. You may have to follow up with additional information if the credit reporting agency requests more details or documents. Unfortunately, many mixed files are not resolved through the informal dispute process and only a lawsuit can get the credit report cleaned up. If you've disputed your mixed file and haven't gotten it fixed yet, your next step should be to talk to an attorney who is familiar with credit reporting issues and can advise you of your rights under the Fair Credit Reporting Act.