FICO is not a single score
When people say "my credit score," they usually mean a FICO score — but FICO (Fair Isaac Corporation) has released dozens of scoring models over its history, and the version a lender pulls depends on the product, the bureau, and the lender's own preferences. There is no single FICO score. There are scores generated by different models, applied to data at each of the three bureaus, producing potentially six or more different numbers for the same consumer at the same moment.
Understanding the model landscape is essential to understanding why your "score" varies.
The 300–850 range
All modern FICO consumer credit scores use a 300–850 scale. The higher the number, the lower the risk in the eyes of the model. A 300 represents the highest possible credit risk; 850 represents a perfect score. Most consumers fall between 580 and 780. Less than 2% of Americans hold a perfect 850.
The score itself is a prediction of the probability that you'll go 90 days past due on any credit obligation within the next 24 months. It doesn't measure financial health directly — it measures predicted repayment behavior.
FICO score factors
Every FICO model weighs five categories:
- Payment history (35%) — whether you pay on time. This is the single largest factor.
- Amounts owed / utilization (30%) — how much of your available revolving credit you're using.
- Length of credit history (15%) — how long accounts have been open.
- Credit mix (10%) — whether you have both revolving and installment accounts.
- New credit (10%) — recent hard inquiries and newly opened accounts.
The weights vary slightly between model versions, but this is the general framework.
FICO 8: the most widely used model
FICO 8 was released in 2009 and remains the most commonly used version by general lenders — credit cards, personal loans, and many auto lenders. If a lender runs a credit check without specifying a model, there's a reasonable chance it's FICO 8.
Key characteristics of FICO 8:
- More sensitive to high utilization than earlier models
- Ignores collection accounts with an original balance under $100
- Treats authorized user tradelines, which some consumers use strategically to boost scores
- Does not distinguish between medical and non-medical collections
If you're monitoring your score through a bank or credit card's free score feature, it's often FICO 8 from one bureau — but confirm which bureau it's pulling from.
FICO 9: better on medical debt and collections
FICO 9 was released in 2014 and includes two important changes from FICO 8:
- Paid collections carry no weight. Once a collection account is paid, FICO 9 ignores it entirely. Under FICO 8, a paid collection still drags your score.
- Medical collections are weighted less heavily. FICO 9 recognizes that medical debt is a poor predictor of credit repayment behavior and reduces its impact accordingly.
Despite being a better model for consumers, FICO 9 adoption by lenders has been slow. Most major credit card issuers and many banks still use FICO 8. The mortgage industry almost exclusively uses older versions (FICO 2, 4, and 5 — discussed below).
FICO 10 and FICO 10T: the newest models
FICO 10 and FICO 10T were released in 2020. FICO 10 is a standard update; FICO 10T adds trended data — it looks at your utilization and payment history over 24 months rather than just the most recent snapshot.
FICO 10T rewards consumers who consistently pay down balances. It penalizes consumers who carry growing balances even if current payments are on time. It's a more nuanced model but has seen limited lender adoption as of this writing.
Mortgage industry uses older models
This surprises many consumers. When you apply for a mortgage, lenders are required by Fannie Mae and Freddie Mac guidelines to pull FICO 2 (Experian), FICO 4 (TransUnion), and FICO 5 (Equifax). These are models from the late 1990s and early 2000s.
The mortgage industry uses older models because the guidelines haven't been updated to allow newer ones at scale. A 2022 FHFA announcement indicated that FICO 10T and VantageScore 4.0 would eventually be required for conforming loans, but the rollout has been gradual.
The practical implication: your FICO 8 score shown in a bank app may be significantly different from your mortgage FICO score. Consumers are often surprised when their mortgage pull comes back lower than expected.
Auto and industry-specific FICO scores
FICO also produces industry-specific versions:
- FICO Auto Score — used by auto lenders, emphasizes auto loan payment history
- FICO Bankcard Score — used by credit card issuers
- Both range from 250–900, not 300–850
These versions put more weight on how you've handled similar credit products in the past.
Why your score differs across bureaus
Each bureau — Equifax, Experian, TransUnion — has different data in your file. Creditors don't always report to all three bureaus. An account that appears on one report may not appear on another. This means your FICO score at each bureau is calculated on different underlying data, producing different results.
When a lender says they pulled your "FICO score," the full answer is: which FICO version, from which bureau.
Your next step
If you're preparing for a major credit application, pull your reports from all three bureaus at AnnualCreditReport.com. Check for any negative items that could be disputed and removed before the lender runs their check. For a mortgage, prioritize your Equifax, Experian, and TransUnion reports equally — lenders use the middle of the three mortgage FICO scores to make their decision.