The Case of the Duplicate Social: Fixing Mixed Credit Files
When we think of identity theft, we often imagine a bad actor deliberately stealing someone’s personal information. But there’s another, often overlooked credit crisis that can be just as devastating: the mixed credit file. This occurs when two people—usually with similar names, birthdays, or Social Security numbers—have their credit profiles merged in the records of one or more credit bureaus. The result is a jumbled credit report full of inaccurate data, mysterious accounts, and unexplained score changes.
In this 2000-word case study introduction, we examine how one borrower uncovered, addressed, and resolved a complex case of mixed credit files caused by a duplicated Social Security number. We’ll explore how this incident affected her Middle Credit Score®, how she navigated disputes with multiple bureaus, and what steps she took to correct the confusion permanently.
This case is especially important for borrowers who:
- Are seeing unfamiliar accounts on their credit reports
- Have been denied credit due to someone else’s debts
- Notice drastically different scores between the three bureaus
- Suspect their file may be incorrectly tied to a relative or stranger
It’s also a critical read for anyone in shared living arrangements (e.g., twins, siblings, roommates) where address overlaps may increase the risk of mixed files.
In our case, 32-year-old Sara had never missed a payment in her life. She prided herself on maintaining excellent credit and carefully monitoring her finances. But when she applied for a mortgage, her lender flagged a problem: one of her credit reports listed a bankruptcy, two auto loans, and five credit cards—none of which were hers.
Worse, her Experian report showed a score of 612, dragging her Middle Credit Score® below the qualifying threshold. Her Equifax and TransUnion scores remained in the 700s.
Sara was shocked. Her lender suspected identity theft. But when she pulled her reports, the picture became clearer: the unfamiliar accounts belonged to another woman with the same name and a nearly identical Social Security number—off by one digit. Somewhere along the line, the bureau’s system had merged their data.
This launched a six-month journey involving:
- Disputes with all three bureaus
- A notarized affidavit confirming her identity
- A line-by-line review of 18 credit entries
- A formal FCRA Section 611 investigation
- A consumer complaint filed with the CFPB
This case study follows Sara’s exact steps, from the moment of discovery to the final resolution, and includes detailed strategies for:
- Spotting the signs of a mixed file
- Drafting effective dispute letters for non-fraudulent errors
- Using Social Security verification to untangle records
- Protecting your Middle Credit Score® during a bureau dispute
- Escalating to the CFPB when bureaus don’t cooperate
Mixed file cases like Sara’s are more common than most people think—and they disproportionately affect borrowers with common names, generational name suffixes (Jr., Sr., II), and those with similar addresses or birth dates to others in their region.
Correcting a mixed file is not the same as resolving identity theft. You’re not claiming fraud—you’re proving mistaken identity and demanding bureau correction under the Fair Credit Reporting Act (FCRA). And in many cases, it requires an even higher burden of documentation.
By the end of this case study, you’ll understand how to:
- Defend your credit from someone else’s debts
- Restore your true credit profile
- Maintain score stability while errors are being corrected
Let’s dive into Sara’s story and examine what every borrower needs to know when their credit file gets mixed up—and their Middle Credit Score® takes the hit.
Full Case Walkthrough: Sara’s Six-Month Fight to Restore Her Middle Credit Score®
Step 1: Discovery During Mortgage Pre-Approval
Sara’s journey began like many others—during a mortgage pre-approval. Her loan officer pulled a tri-merge credit report and immediately noticed a problem. While Equifax and TransUnion both reported scores in the 730s, Experian showed a 612. Worse, it listed several unfamiliar accounts:
- A bankruptcy filed five years prior
- Two auto loans from out-of-state
- Five open credit cards in default
The Middle Credit Score® calculated from the three reports came out to 612, effectively disqualifying her from the best mortgage rates—and in some cases, mortgage approval altogether.
Step 2: Pulling Her Credit Reports Individually
Sara went home and pulled all three of her credit reports individually using AnnualCreditReport.com. While Equifax and TransUnion looked normal, Experian showed:
- A second mailing address in Ohio
- A bankruptcy from a different court district
- Several accounts from banks she’d never heard of
This wasn’t fraud—it was a mixed file. Sara and the other woman shared a first and last name, birth year, and the first 8 digits of a Social Security number. The final digit had been keyed incorrectly somewhere in the system, causing Experian’s algorithms to merge both profiles.
Step 3: Creating a Dispute Packet
Sara gathered the following documents:
- A copy of her Experian credit report with errors highlighted
- A copy of her driver’s license and Social Security card
- Proof of current address (utility bill)
- A notarized affidavit swearing to her identity
- A letter formally disputing the mistaken entries under FCRA Section 611
She sent this dispute via certified mail with return receipt to Experian’s dispute department.
Step 4: Experian’s Response
Three weeks later, Experian sent back a form letter stating: “We verified the information you disputed with the source and have found it to be accurate.”
Sara was furious. She called Experian’s support line, but couldn’t reach a human who understood the problem. So she escalated.
Step 5: Filing a CFPB Complaint
Using consumerfinance.gov, Sara filed a complaint with the Consumer Financial Protection Bureau. She uploaded all documents from her original dispute and explained that:
- The accounts belonged to a different individual
- The error was due to a miskeyed Social Security number
- Experian had failed to conduct a meaningful investigation
Within 15 days, Experian was required to respond to the CFPB.
Step 6: Results and Reinvestigation
Following the CFPB complaint, Experian reopened the investigation. This time, they:
- Contacted the original furnishers (banks)
- Cross-referenced the SSN suffix
- Verified Sara’s address history didn’t match the disputed data
Two weeks later, she received a letter stating:
“Based on new documentation, the following items have been deleted from your credit report.”
All five credit cards, two auto loans, and the bankruptcy were removed.
Step 7: Monitoring Score Recovery
Within 10 days of the deletion, Sara’s Experian score jumped from 612 to 728. Her new Middle Credit Score® was 728—restored to where it belonged.
She continued to monitor her reports monthly and requested confirmation from her lender that the new score had been reflected in her mortgage application.
Lessons from Sara’s Case
- Mixed Files Are Not Identity Theft They require a different dispute strategy. Rather than proving fraud, you must prove misidentification.
- The Burden of Proof Is on You Don’t wait for the bureau to figure it out. Provide ID, proof of address, and detailed letters.
- Use Certified Mail Always create a paper trail with return receipts for disputes.
- Escalate to the CFPB When Ignored The CFPB holds bureaus accountable and forces proper reinvestigation.
- Protect Your Middle Credit Score® One bureau’s mistake can tank your score and hurt your loan eligibility. Always monitor all three bureaus.
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