Key takeaways
- Mortgage lenders use older FICO models, not the score in your banking app.
- With two borrowers, lenders typically use the lower of the two middle scores.
- Utilization is the fastest lever — paying balances below 10% can move a score within one cycle.
- Score tiers at 680, 700, 720, and 760 produce real pricing differences.
The score your lender pulls is not the one you see
Mortgage underwriting uses specific legacy FICO versions — commonly FICO 2, 4, and 5 across the three bureaus — because those are what the government-sponsored enterprises require. Consumer apps typically display VantageScore or a newer FICO version, which can differ by twenty points or more in either direction.
Lenders pull all three bureaus and use the middle of the three scores. With co-borrowers, most programs use the lower of the two middle scores. Improving the stronger borrower's file accomplishes nothing if the other borrower is the constraint.
What moves a score quickly
Credit utilization is roughly 30% of a FICO score and updates every statement cycle, which makes it the fastest lever available. Paying revolving balances below 10% of limits — including on cards you rarely use — can produce a meaningful jump within 30 to 45 days. Requesting a credit limit increase achieves a similar effect without paying anything down.
Do not close old accounts before applying; it shortens average account age and reduces available credit. Do not open new accounts either. Dispute genuine errors, which appear on a meaningful share of reports, and ask about rapid rescore through your lender — it can update corrected information in days rather than a full cycle.
How tiers translate into money
Conventional loan pricing uses loan-level price adjustments that step at defined score and LTV thresholds. Crossing from 679 to 680, or 719 to 720, can change your rate or your cost meaningfully. A borrower in the mid-600s and one above 760 on the same loan can face a spread well over half a percentage point.
Over thirty years on a $400,000 loan that spread is six figures. Two months spent moving a score across a threshold is among the highest hourly-rate work available to a homebuyer. Compare scenarios in our loan comparison calculator.
Frequently asked questions
Will rate shopping hurt my score?
Barely. Mortgage inquiries within a 14 to 45 day window are treated as a single event by FICO scoring models. Shop deliberately and compress it into a short period.
What if I have no credit history?
Some lenders build a nontraditional credit file from rent, utility, and insurance payment histories. FHA and manual underwriting accommodate this; automated underwriting generally does not.
Do medical collections still count?
The bureaus removed paid medical collections and those under $500 from consumer reports, and mortgage scoring models weight remaining medical debt less heavily than other collections. It still matters, just less than it used to.
Sources & further reading
- Fannie Mae Loan-Level Price Adjustment Matrix
- Consumer Financial Protection Bureau, Credit reports and scores
- FICO scoring model documentation
Figures and rules change. Verify current requirements with the issuing agency or a licensed professional before acting.