When two people apply for a mortgage together, lenders don’t simply pick the higher score or average both applicants’ scores in the way you might expect. The general rule is that the lower of the two applicants’ middle credit scores carries the most weight, though the exact method depends on the loan type. Understanding how this works can save you thousands of dollars over the life of a loan, and in some cases, it may change whether you decide to apply jointly at all.
How Lenders Pick a “Representative” Score
Each applicant on a mortgage typically has three credit scores, one from each major bureau (Equifax, Experian, and TransUnion). The lender first finds each person’s middle score. If a bureau only returns two scores, the lower of the two is used. That middle (or lower) number becomes your representative credit score.
When there’s only one borrower, the representative score is straightforward. On a joint application with two or more borrowers, Fannie Mae’s current guidelines call for using the average of the borrowers’ median scores. So if your middle score is 760 and your co-borrower’s middle score is 680, the lender would average those to get 720 for qualification purposes. This averaged approach is relatively new in Fannie Mae’s guidelines, replacing an older rule that simply used the lowest middle score outright.
Not every loan program works this way, though. The score that matters, and how it’s calculated, varies by whether you’re getting a conventional loan, an FHA loan, a VA loan, or a USDA loan.
Conventional Loans
Conventional loans backed by Fannie Mae or Freddie Mac follow the averaging method described above. The lender takes each borrower’s median credit score and then averages them. That averaged number is what determines your eligibility and, along with other factors like your down payment and loan-to-value ratio, the interest rate you’re offered.
This averaging approach gives joint applicants a small cushion compared to the old method. If one borrower has a significantly lower score, the average will still be pulled down, but not as far as if the lender simply used the lower score alone. That said, lenders still set minimum score thresholds. If either borrower’s individual score falls below the lender’s minimum (often 620 for conventional loans), the application may be denied regardless of the average.
FHA, VA, and USDA Loans
Government-backed loan programs have their own rules. FHA loans generally look at the lower of the two borrowers’ middle scores when determining eligibility and pricing. That means one applicant’s weak credit history can directly control the terms of the entire loan.
USDA direct loans evaluate each applicant’s credit separately. The program uses the middle score when three scores are available, or the lowest score when only two are reported. Each borrower is judged on their own merits, and the USDA is explicit that a borrower with good credit cannot compensate for a co-applicant with poor credit. For USDA Section 502 loans, a score of 640 or above allows for a streamlined credit review, while scores below that trigger additional verification steps, including proof of rent or mortgage payment history.
If you live in a community property state, USDA loans add another layer. Even if your spouse isn’t on the application, the lender must pull their credit report and factor their debts into your total obligations. Your spouse’s credit history alone can’t be used to deny you, but their outstanding debts can reduce the loan amount you qualify for.
How the Lower Score Affects Your Rate
The credit score used on your application doesn’t just determine approval. It directly influences the interest rate the lender offers. Mortgage pricing is tiered: borrowers with scores above 740 generally get the best rates, while each step down (720, 700, 680, and so on) typically adds to the cost.
Even a modest difference matters over a 30-year mortgage. A rate that’s a quarter of a percentage point higher on a $350,000 loan adds roughly $55 per month, which works out to nearly $20,000 in additional interest over the life of the loan. If the lower score on a joint application also pushes you into a bracket that requires private mortgage insurance (PMI), the monthly cost climbs further. PMI premiums themselves are partly based on credit score, so a lower score means higher premiums on top of a higher rate.
When Applying Solo Makes More Sense
If one applicant has strong credit and the other doesn’t, applying with just the higher-scoring borrower can result in a better rate and lower overall costs. This is a legitimate and common strategy. The trade-off is that you lose the other person’s income when the lender calculates how much you can borrow. Your debt-to-income ratio, which compares your monthly debt payments to your gross monthly income, is based only on the applicant(s) on the loan.
This approach works best when the higher-scoring borrower earns enough on their own to qualify for the loan amount you need. If you’re stretching to afford a home and need both incomes to qualify, dropping a co-borrower may shrink your borrowing power more than the rate improvement saves you. Run the numbers both ways: the monthly payment at a higher rate with both incomes versus a lower rate with one income and a smaller loan.
Keep in mind that not being on the mortgage doesn’t prevent someone from being on the property’s title. Your partner or spouse can still co-own the home even if only one of you is on the loan. The lender cares about who is financially responsible for repayment, which is separate from who legally owns the property.
Improving the Lower Score Before You Apply
If your timeline allows it, boosting the weaker credit score before applying is often the most effective strategy. Even a 20- to 40-point improvement can shift you into a better pricing tier. Focus on the factors that move scores fastest: paying down credit card balances to lower your utilization ratio (the percentage of your available credit you’re using), correcting errors on your credit report, and avoiding new credit applications in the months before your mortgage.
Paying revolving balances down to 30% or less of each card’s limit can produce noticeable score gains within one to two billing cycles. Disputing inaccurate late payments or accounts that don’t belong to you can also help, though the dispute process can take 30 to 45 days per item. If timing is tight, ask the lender for a rapid rescore, a process where the lender works with the credit bureaus to quickly update your report after you’ve paid down a balance or resolved an error. Not all lenders offer this, but many do, and it can shave weeks off the waiting period.
Planning ahead by three to six months gives you the most flexibility. That window is usually enough to reduce utilization, let any recent hard inquiries age slightly, and resolve any disputes, all of which can meaningfully move the score that ultimately determines your mortgage terms.