# FICO Score 4: The Mortgage Score Most People Never See

> FICO Score 4 is the TransUnion version of the Classic FICO scores mortgage lenders use. Most people have never seen theirs, and it can sit a long way from the number their app shows.

Source: https://phonenumbercreditscore.com/blog/fico-score-4-explained  
Author: Jordan Avery, Head of Content  
Published: 2023-04-19  
Updated: 2024-06-14  
Topic: Credit Scores  
Publisher: Phone Number Credit Score (https://phonenumbercreditscore.com/)

FICO® Score 4 is the credit score FICO calculates from your TransUnion file using one of its older "Classic" models, and it's the TransUnion score most mortgage lenders pull when you apply for a home loan. It runs from 300 to 850 like the scores you know. The difference is that almost nobody sees it until a loan officer reads it to them, and it's often lower than the number in their phone.

We hear some version of this all the time. Someone spends a year watching a free app say 742, sits down with a lender, and the TransUnion mortgage score comes back 709. Nothing broke. They were watching a different model, and the lender was reading FICO Score 4.

## Where FICO Score 4 fits in the FICO family

FICO doesn't make one score. It makes generations of scores (FICO 2, 4, 5, 8, 9, 10, 10T) plus industry versions for auto and card lending, and each credit bureau runs its own set. When a mortgage lender orders credit on a conforming loan, they ask for one specific Classic FICO from each of the three bureaus:

| Bureau | Mortgage score | Name you may see on paperwork |
|---|---|---|
| Experian | FICO Score 2 | Experian/Fair Isaac Risk Model V2 |
| TransUnion | FICO Score 4 | FICO Risk Score, Classic 04 |
| Equifax | FICO Score 5 | Equifax Beacon 5.0 |

Those three names come straight from [Fannie Mae's Selling Guide on credit score requirements](https://selling-guide.fanniemae.com/sel/b3-5.1-01/general-requirements-credit-scores), which tells lenders exactly which versions to order with the tri-merge report. myFICO lays out the same pairing on its page about [the different FICO Score versions](https://www.myfico.com/credit-education/credit-scores/fico-score-versions), alongside the auto and bankcard variants.

So when someone says "my mortgage score," they really mean three scores, and FICO 4 is the TransUnion third. If you want the full trio explained side by side, we cover it in [mortgage credit scores: FICO 2, 4 and 5](https://phonenumbercreditscore.com/blog/mortgage-credit-scores-fico-2-4-5). This post stays on the TransUnion one.

## Why lenders still use a model this old

Fannie Mae and Freddie Mac require it. The FHFA's 2022 release on new score models says it plainly: "For nearly 20 years, the Enterprises have relied on Classic FICO." A lender that wants to sell its loans to the Enterprises (which is most conforming lenders) has to underwrite with the scores the Enterprises accept.

Inertia does the rest. Pricing grids, investor overlays and automated underwriting rules have been tuned to Classic FICO for years, and swapping the score means re-tuning all of it.

## The score in your app is probably a different model

Most free apps show a VantageScore 3.0 (Credit Karma does, for example), and many bank apps and card statements show FICO Score 8. Both are perfectly good scores. They just aren't the TransUnion mortgage score, and the model differences are big enough to move the number a lot.

Three differences do most of the damage:

- **Small collections.** According to myFICO, [collections with an original balance under $100 are disregarded by FICO Score 8, 9 and the 10 suite](https://www.myfico.com/credit-education/faq/negative-reasons/collections-affect-credit). FICO 4 is older than that rule, so a forgotten $60 gym collection can still count against it.
- **Paid collections.** FICO 9 stopped penalizing paid third-party collections. FICO 4 doesn't make that distinction. A paid collection that's still on the report can still weigh on the score.
- **Different builders entirely.** VantageScore is a separate company's model with its own formula. Comparing a VantageScore 3.0 to a FICO 4 is like comparing two different thermometers in two different rooms.

The app isn't wrong, it's answering with a different formula. For the longer version, our piece on [why your Credit Karma score differs from a lender's](https://phonenumbercreditscore.com/blog/why-credit-karma-score-differs-from-lender) walks through it, and [FICO vs. VantageScore](https://phonenumbercreditscore.com/blog/fico-vs-vantagescore) covers the models head to head.

![A person filling in printed loan paperwork with a pen and calculator, the kind of form where a FICO Score 4 ends up](https://phonenumbercreditscore.com/media/blog/01a1366e-f38c-7e43-88ed-008476592d13-1200.webp)

## How the middle-score rule turns FICO 4 into a rate

On a typical conforming loan, the lender pulls all three Classic FICO scores and uses the middle one. For two borrowers, they take each person's middle score and use the lower of the two. myFICO describes the same rule, and any loan officer will tell you the same.

Take a fictional couple, Renee and Marcus Hale:

| | FICO 2 (Experian) | FICO 4 (TransUnion) | FICO 5 (Equifax) | Middle |
|---|---|---|---|---|
| Renee | 748 | 731 | 755 | **748** |
| Marcus | 702 | 688 | 694 | **694** |

The loan is priced at 694, Marcus's middle score. Notice that Renee's FICO 4 was her lowest score and didn't matter at all, because it wasn't her middle. Marcus's FICO 4 was also his lowest. If it had been 700 instead of 688, his middle would still be 694. FICO 4 decides the price only when it *is* someone's middle score. When it's the low outlier, fixing whatever drags it down may not move the rate at all. Know that before you pay anyone to chase points.

## What actually moves a FICO Score 4

FICO publishes general weights for its scores: payment history about 35%, amounts owed about 30%, length of history 15%, new credit 10% and credit mix 10%. They shift from person to person, so read them as a map of the levers, not a recipe.

**Late payments.** A 30-day late in the last year usually hurts more than anything else on this list. Older lates matter less as they age.

**Card balances.** Utilization comes from the balances your issuers report, which is usually the statement balance. FICO 4 reads a snapshot, not a trend, so paying cards down before the statement closes shows up on the next report. We go deep on this in [credit utilization explained](https://phonenumbercreditscore.com/blog/credit-utilization-explained).

**Collections.** Since FICO 4 doesn't forgive small or paid collections the way newer models do, getting an inaccurate collection removed (through a dispute, if it really is wrong) can help it more than it would help FICO 9.

**Medical debt changes.** This one helps without you doing anything. The three bureaus stopped reporting paid medical collections in July 2022 and medical collections under $500 in April 2023, which the CFPB [explained in plain terms here](https://www.consumerfinance.gov/archive/blog/medical-debt-anything-already-paid-or-under-500-should-no-longer-be-on-your-credit-report/). If a $300 medical collection was dragging down your FICO 4, it should no longer be on the file the score reads.

**Hard inquiries.** FICO counts a cluster of mortgage inquiries as one search. Older versions like FICO 4 use a 14-day window (newer ones use 45 days), so keep your rate shopping inside two weeks. A new card the month before you apply gets no such grace.

## What's changing, and when

In October 2022 the FHFA [validated FICO 10T and VantageScore 4.0](https://www.fhfa.gov/news/news-release/fhfa-announces-validation-of-fico-10t-and-vantagescore-4.0-for-use-by-fannie-mae-and-freddie-mac) for Fannie Mae and Freddie Mac loans, and said lenders would eventually deliver two bureau reports instead of three. Both new models can use trended data, meaning they look at how your balances moved over time and not just where they sat on one day.

The timing has shifted since. In its [February 2024 update](https://www.fhfa.gov/news/news-release/fhfa-announces-key-updates-for-implementation-of-enterprise-credit-score-requirements), the FHFA said the move to the new score requirements and bi-merge reporting is expected in the fourth quarter of 2025, with historical VantageScore 4.0 data published earlier so lenders can prepare.

Until then, Classic FICO is the requirement, and the date has already moved once. Our guess is that FICO 4 stays on mortgage paperwork for a while. Outside the Enterprise rules, plenty of lenders, landlords and businesses will keep using it regardless.

## Who else looks at FICO Score 4

Mortgage underwriting is the headline use, but it's not the only one. TransUnion's industry versions, FICO Auto Score 4 and FICO Bankcard Score 4, come from the same generation and show up in some auto and card decisions. Plenty of people who aren't mortgage lenders use the base FICO 4 for a simple reason: it's the TransUnion number an underwriter would see.

That's why it's the score we chose. When a landlord checks a rental applicant or a broker pre-qualifies a borrower through us, they get the real FICO Score 4, calculated by FICO from TransUnion data, along with the top reasons it isn't higher. We explain the choice in more detail on our [why FICO Score 4 page](https://phonenumbercreditscore.com/why-fico-4).

## How to see your own FICO Score 4

Free apps generally won't show it. You've got three routes:

1. **Buy it directly.** myFICO sells three-bureau reports that include the mortgage versions.
2. **Ask a mortgage lender.** If you're pre-qualifying anyway, ask the loan officer to tell you all three scores and which one is your middle.
3. **Look yourself up.** Through us you can check your own number. You always have a permissible purpose for your own file, and it's a soft pull, so it never touches your score.

Whatever route you take, write down the date and the number. Scores move monthly as new balances report, and a FICO 4 from March doesn't tell you much about July.

## Reading someone else's FICO 4 with a fair eye

On the business side, three habits make the number far more useful:

- **Read the reasons, not just the score.** "Proportion of balances to credit limits is too high" on a 668 is a very different person than "serious delinquency" on a 668. The first may be a 720 in two months.
- **Check the file age.** A 690 built over 15 years and a 690 on a two-year-old file aren't the same risk. If the file is very new, our post on [thin credit files](https://phonenumbercreditscore.com/blog/thin-credit-file) is worth a read.
- **Get permission first.** Every lookup needs a permissible purpose under the FCRA, and the simplest one is the person's written OK. Our [soft pull vs. hard pull](https://phonenumbercreditscore.com/blog/soft-pull-vs-hard-pull) guide explains why a soft pull leaves no mark on them.

For loan officers in particular, knowing the TransUnion mortgage score before the first real conversation changes the call. You can tell a borrower whether they're a paydown away from the next pricing tier, or whether they need six months of clean history first, and that kind of straight answer is how a pre-qualification turns into a closed loan. We cover that workflow in [qualifying mortgage leads](https://phonenumbercreditscore.com/blog/mortgage-loan-officer-lead-qualification).

## Frequently asked questions

### Is FICO Score 4 the same as FICO 8?

No. Both are built by FICO and both run from 300 to 850, but FICO 8 is a newer model with different rules. FICO 8 ignores collections with an original balance under $100, for example, and FICO 4 predates that change. The same TransUnion file can produce two different numbers.

### Who uses FICO Score 4 besides mortgage lenders?

TransUnion's industry versions, FICO Auto Score 4 and FICO Bankcard Score 4, are built on the same generation and show up in some auto and card lending. Landlords, brokers and small businesses also use the base FICO Score 4 because it's the number a mortgage underwriter would see from TransUnion.

### Does checking my own FICO Score 4 hurt my credit?

No. Checking your own score is a soft inquiry. It never affects any of your scores, and lenders can't see it.

### Is FICO Score 4 being replaced?

Eventually. The FHFA validated FICO 10T and VantageScore 4.0 for Fannie Mae and Freddie Mac loans in October 2022, and its February 2024 update pointed to a transition expected in the fourth quarter of 2025. Until that happens, Classic FICO, including FICO Score 4 from TransUnion, is still what conforming mortgage lenders pull.