If you've spent any time in the mortgage industry, you've pulled a tri-merge credit report. But do you know what's actually happening behind the scenes? Where does that data come from, who maintains it, and why does the same borrower sometimes have three different scores?

The answer starts with the credit reporting agencies — the organizations that collect, organize, and sell consumer credit data to lenders like you.

The Short Definition

A credit reporting agency (CRA), also commonly called a credit bureau, is a company that gathers financial and personal data on consumers, compiles it into credit reports, and generates credit scores. Mortgage lenders use these reports and scores to evaluate a borrower's creditworthiness before extending a loan.

In the U.S. mortgage industry, the three major CRAs are Equifax, Experian, and TransUnion. You'll encounter all three on virtually every residential loan file you work.

What Data Do They Collect?

Credit reporting agencies compile data from a wide range of sources, primarily creditors — banks, credit card companies, auto lenders, student loan servicers, and others who voluntarily report payment activity. The data typically includes:

• Payment history: Whether a borrower pays on time, late, or not at all. This is the most heavily weighted factor in most scoring models.
• Account balances and credit limits: How much revolving credit is being used relative to what's available — this is called credit utilization.
• Account types and age: The mix of installment loans (like mortgages and auto loans) vs. revolving accounts (like credit cards), and how long those accounts have been open.
• Public records and collections: Judgments, tax liens, bankruptcies, and accounts sent to collections — though some of these have been removed from reports in recent years following regulatory changes.
• Inquiries: Hard inquiries (when a lender pulls credit for a loan application) vs. soft inquiries (like a borrower checking their own credit).

Important: Creditors are not required to report to all three bureaus — or any of them. This is why your borrower's data may differ across Equifax, Experian, and TransUnion.

Why Are There Three Of Them?

The three major CRAs operate independently and compete for business. They each gather data separately, maintain their own databases, and use different proprietary systems. This is why pulling a tri-merge report — a combined report from all three bureaus — is standard practice in mortgage underwriting.

Because lenders report voluntarily and not always to all three bureaus, a borrower can have accounts that appear on one bureau's report but not others. The result: three different credit profiles, and often three different scores.

For mortgage qualifying purposes, most conventional and government loan programs use the middle score of the three bureau scores. If there are multiple borrowers on the loan, lenders typically use the lower middle score of all applicants.

CRAs vs. Credit Scoring Models: Know The Difference

This is where a lot of people — even experienced mortgage pros — get fuzzy. The credit reporting agencies don't create the scores themselves. They supply the data; the scores are generated by scoring models built by separate companies.

FICO (Fair Isaac Corporation) is the dominant scoring model in mortgage lending, though the specific version matters — FICO Score 2 (Experian), FICO Score 5 (Equifax), and FICO Score 4 (TransUnion) are the versions most commonly used in residential mortgage underwriting as of this writing. VantageScore is another model developed jointly by the three bureaus, but it's more commonly used in consumer-facing contexts than in mortgage origination.

Think of it this way: the CRA is the library, and the scoring model is the algorithm that decides what the books are worth.

The Regulatory Framework

CRAs don't operate in a vacuum. They're heavily regulated under the Fair Credit Reporting Act (FCRA), which governs how consumer data is collected, shared, and corrected. As a mortgage professional, you need to understand your obligations under the FCRA when you pull credit — including adverse action requirements when a loan is denied.

Consumers have the right to dispute inaccurate information on their credit reports, and CRAs are required to investigate and correct errors within a defined timeframe. Disputed accounts can complicate or delay the mortgage process, so it's worth knowing when a borrower is in the middle of a dispute before you pull their credit.

What MLOs Should Watch For

A few practical things worth keeping top of mind when it comes to credit reporting agencies:

Frozen credit: Borrowers who have placed a security freeze on their credit (increasingly common after data breaches) will need to temporarily lift the freeze before you can pull their report. This can add time to your process.

Rapid rescoring: If a borrower has an error on their report or needs to pay down a balance to hit a qualifying score, rapid rescoring is a service — offered through your credit reporting vendor, not directly through the bureaus — that can update scores faster than waiting for the standard reporting cycle.

Mortgage inquiries and rate shopping: Multiple mortgage-related hard inquiries within a short window (typically 14–45 days depending on the scoring model) are generally treated as a single inquiry to minimize the score impact of rate shopping. Make sure your borrowers understand this when they're nervous about having their credit pulled.

The bureaus aren't infallible: Errors on credit reports are more common than most people realize. If something looks off on a tri-merge, it may be worth asking your borrower to review their full reports.

The Bottom Line

Credit reporting agencies are the foundation of the credit evaluation process. As an MLO, you're relying on their data every time you pull a file. Understanding how they collect information, why scores vary across bureaus, and how the regulatory framework works will make you a sharper originator and a more credible resource for your borrowers.

The three bureaus aren't interchangeable — they're three independent databases with three separate versions of your borrower's financial story.