Your score is not one number, it is three
A credit score is a single number between 300 and 850 that predicts one thing: how likely you are to repay debt on time. Higher means safer from the lender's point of view. That is all it is. It is a reliability score.
It is not a measure of how much money you have. It is not a measure of your character. It does not know your income, your job, or your savings balance. Those get graded in their own buckets, because credit is only one of the five things a lender is actually weighing. It is a statistical guess about future payment behavior based on past payment behavior.
Now the part that surprises people. You do not have a score. You have several. The brand mortgage lenders use is FICO, and you have a FICO score at each of the three major credit bureaus, Equifax, Experian, and TransUnion. A credit bureau is a company that collects your payment history from the lenders you already owe and sells it back to lenders considering you next. The three numbers are often different from one another, because not every creditor reports to all three and they do not all report on the same day.
Then there is the score in your banking app. That is usually a VantageScore, or a recent FICO version such as FICO 8. Mortgage lenders pull older FICO versions, and they do it on purpose, because those versions are what the agencies that write conventional loan rules require. A conventional loan, since the word appears everywhere, is one that follows the rules set by Fannie Mae and Freddie Mac, the two government sponsored companies that buy a large share of the mortgages made in this country.
The practical consequence is that the free score and the mortgage score are two different measurements of the same person, and the gap between them is routinely twenty points or more in either direction. Treat the free number as an estimate. It tells you roughly where you sit and whether you are trending up or down. It does not tell you what a lender will see, and you will not know that until one pulls it.
The five ingredients, and how much each one weighs
The score is built from five ingredients, and they are not equally important.
- Payment history, about 35 percent. Did you pay on time. This is the single largest slice and also the simplest. A payment thirty days late does real damage, and the damage fades slowly.
- Amounts owed, about 30 percent. Mostly credit card utilization, meaning how much of your available limits you are using. A card at 90 percent of its limit hurts even if you pay it in full every month, because the balance reported to the bureau is usually the statement balance.
- Length of credit history, about 15 percent. How long your accounts have been open. This is why closing your oldest card is usually a mistake.
- New credit, about 10 percent. Recent applications and new accounts.
- Credit mix, about 10 percent. Whether you have handled different kinds of credit.
Translation: pay on time and keep card balances low, and you have already won roughly two thirds of the score. The other three ingredients matter, but they are not where the leverage is.
Mortgage quirk number one, the middle score
Here is the first thing that makes mortgages different. A mortgage lender pulls all three bureaus and uses your middle score.
Not the average. Not the highest. The middle one.
If your three scores come back as 690, 712, and 740, the lender uses 712. The 740 does not help you and the 690 does not hurt you. Only the middle number goes into the file.
That matters practically, because one bureau reporting something strange can quietly reshape your result. If a collection account appears at only one bureau, it may pull that bureau's score down without touching your middle score at all, in which case it is a smaller problem than it feels like. Or it may be the very number that drags your middle score down a tier, in which case it is worth fixing before you apply.
Mortgage quirk number two, what happens when two of you apply
This is the rule that catches people.
If you and a partner apply together, each person's middle score is pulled, and what happens next depends on the program. Conventional pricing now generally runs off the average of the two middle scores, while FHA and most manual underwrites use the lower of the two.
Two definitions before we go further. FHA means a loan insured by the Federal Housing Administration, a government agency that insures lenders against loss so they can approve files that conventional rules would turn away, generally in exchange for a lower minimum down payment and more forgiving credit standards. How FHA stacks up against conventional, VA, and USDA is worth settling before you assume which one fits your file. A manual underwrite is a file a human underwriter reviews and decides by hand, rather than one that runs through an automated system and comes back with an answer, and what that reviewer is doing with your paperwork is the part buyers picture least accurately.
The reason this rule confuses everyone is that it changed. For years the lower of the two middle scores governed everything, and that is still what most of the internet says, and still what a lot of people in the business will tell you. Since the agency updates in 2022, conventional pricing generally averages the borrowers' median scores instead. FHA did not follow, and neither did most manual underwriting.
So the honest answer to "does my partner's credit drag us down" is that it depends on which loan you end up using, and that is a question with a specific dollar answer your loan officer can produce before you commit to anything.
Ask your loan officer to price the file both ways before you decide. Then know these three things, because they are your rights and not favors anybody is doing you. The choice of who applies is always yours. A lender may not require your spouse to apply with you. A lender may not discourage either of you from applying.
One more distinction, because these two get confused constantly. Being on the loan and being on the title are different things. The loan is the debt, the promise to repay. Title is the legal record of who owns the property and who holds a claim against it. It is often possible for both partners to be owners on the title while only one is a borrower on the loan. The specifics vary by loan program and by state, so ask out loud rather than assume.
Why a handful of points can be worth real money
Lenders price loans in bands. Your score does not adjust the cost of your loan smoothly, one point at a time. It moves in steps.
Cross a line, for example from the middle 700s into the 740 and above range, and you may land in better pricing. Sit two points below a band line and you get the pricing of the band you are in, not the one you almost reached. Around 580 is the common floor for an FHA loan at the low down payment that program is known for, and how far below 20 percent a down payment can actually go is a separate question from credit, though individual lenders regularly layer their own stricter rules on top of the agency minimum, so the floor you have to clear in practice is often higher than the published one. There are other thresholds below and between.
I am not going to quote a rate here, and you should be suspicious of anyone who quotes one in an article that will still be online in two years. But the bands are real and they are durable. The point is this: a fifteen point improvement that crosses a band line can be worth meaningfully more over the life of the loan than the same fifteen points earned in the middle of a band, where they do nothing at all.
That is why it is worth knowing roughly where you sit before you apply rather than after. If you are just under a line, a small and fast move may pay for itself many times over. If you are sitting comfortably mid band, chasing points is mostly wasted effort and that energy belongs somewhere else. To see why a band matters so much, take a loan amount and two rates a few tenths apart and put them into the interest rate calculator, then watch what the difference does to the monthly payment and to the total interest over thirty years.
What not to do once you are inside a loan
Once your loan is in process, the rule is boring on purpose: change nothing.
Do not open new credit. Do not run up the cards. Do not finance furniture for the house you have not closed on yet, and yes, that happens constantly. Do not close old accounts in an attempt to tidy up, because closing a long standing account can shorten your average history and cut your available limits at the same time. Do not cosign for anybody.
Lenders commonly refresh credit shortly before closing. Every one of those moves can shift the number the approval was built on, and the discovery tends to happen at the worst possible moment. If you are unsure whether something counts, ask before you do it rather than after.
Two borrowers, 728 and 668, and what the program does with them
Take this purely as an example, with numbers chosen to make the rule visible.
Two buyers apply together. Buyer A has bureau scores of 705, 728, and 754, so their middle score is 728. Buyer B has bureau scores of 642, 668, and 690, so their middle score is 668.
On a conventional loan, pricing now generally runs off the average of those two middles. Add 728 and 668, divide by two, and the number that drives the file is 698.
On an FHA loan, or on a conventional file that has to be underwritten by hand, the governing number is 668, the lower of the two.
That is a thirty point spread between two treatments of the same two people, and thirty points is enough to cross a pricing band. It is the reason the program conversation and the credit conversation belong in the same meeting instead of one after the other.
What you do about it is not obvious and it is not mine to decide for you. Ask your loan officer to price the file both ways, jointly and with one borrower, and to show you the qualifying amount alongside the pricing, because a file with one borrower counts only one borrower's income and the amount you qualify for will drop accordingly. Then you choose, and those three rights above are still yours.
The myth that checking your own credit hurts it
People avoid looking at their own credit for years because they believe checking it will lower the score. It will not.
Checking your own credit is a soft pull. A soft pull is an inquiry you requested yourself, one that no lender is using to make a decision about you. It has no effect on your score, no matter how often you do it. A hard pull is the other kind. That is when you apply for credit and a lender pulls your file to decide whether to lend. Hard pulls appear on your report and can cost you a few points each. A real preapproval takes one of those, which is a large part of what separates a preapproval from a prequalification.
There is a second half to this myth worth clearing up. When you shop for a mortgage, multiple lender pulls inside a short window are treated as a single inquiry by the scoring models. How short depends on the model. It is about 14 days on the older FICO versions mortgage lenders pull and about 45 days on newer ones, so do your shopping inside two weeks and you never have to wonder which one applied. The system was deliberately built to let you compare offers without being punished for it. Shopping is expected. So shop.
What to do next
Two small things, and neither one requires talking to a lender.
First, pull your three scores from a free source and find the middle one. Write it down and label it an estimate, because that is what it is. It tells you roughly which band line you are near. It is not the number a lender will see.
Second, look at each of your credit cards and write down how close that specific balance sits to that specific limit. Not the total across all of them. Each one, individually.
The card nearest its limit is the first one to pay down. Utilization is measured account by account as well as across everything you owe, so bringing one nearly maxed card down often moves the score more than spreading the same dollars across three. Of everything on this page, that is the action that tends to pay for itself fastest, and it costs you an evening.
For the loan officers reading this
If you are the one buying, you have what you need. The rest is for originators.
The middle score rule and the two borrower rule are where you earn your fee on day one. Know which version applies to which program, because the 2022 conventional averaging change has not reached most of the internet and clients will arrive with the old rule already in their heads, sometimes having decided something painful because of it.
Run the scenarios early, joint and single borrower, across each program the client could realistically use, before anyone falls in love with a number or a house. Present pricing and qualifying amount side by side, let the client make the call, and document that you did. That is better service and it is cleaner ground than steering anyone toward an answer.
Know the rapid rescore play as well. Paying down a card or correcting a genuine reporting error can lift a score in days rather than months, and sometimes that is the difference between one pricing tier and the next, or between an approval and a denial. It is not available in every situation and it is not a magic trick, but it belongs in your toolkit.
And teach the client which card to pay first. It is the one closest to its limit, not the one with the largest balance, because utilization is measured account by account as well as overall. Clients remember that one, they can act on it the same week, and it costs them nothing but attention.