I pull a lot of credit reports for first time buyers, and the car loan is the debt I see most. It almost never gets someone flat out denied. What it does is quieter. It takes a buyer who could have qualified for one house and quietly turns them into a buyer for a smaller one, and most people never see it happen. If you are just starting out, our first time home buyer Arizona guide covers the full process. This page is only about the car.

How lenders count your car payment

Your car payment goes straight into your debt to income ratio, the same as a student loan or a credit card minimum. The Consumer Financial Protection Bureau defines that ratio simply: all your monthly debt payments divided by your gross monthly income. The new house payment is part of the top number too.

For conventional loans, Fannie Mae's Selling Guide sets the specifics. Here is how it treats the things that usually show up next to a first time buyer's name.

The ceiling on the whole ratio comes from Fannie Mae's B3-6-02. For loans run through Desktop Underwriter, the maximum is 50%. For manually underwritten loans it is 36%, and it can go up to 45% if you meet the credit score and reserve requirements in Fannie Mae's Eligibility Matrix. I never assume a file will get the top number, so I plan with some room to spare.

What a car payment costs you in house

At Freddie Mac's 30 year fixed average of 7.18% for the week of November 5, 2026, every $100 a month of car payment costs you about $14,760 of mortgage you could otherwise qualify for. That is principal and interest only, before taxes, insurance and mortgage insurance.

Here is a simple example. Say you earn $6,000 a month before taxes and carry a $150 credit card minimum. At a 45% ratio, your total monthly debts can reach $2,700. With no car payment, $2,550 of that is available for the full house payment. Add a $550 car payment and the house payment you can carry drops to $2,000. Same person, same job, same credit score.

A $550 car payment does not show up on the listing. It shows up as $81,000 less house.

That gap matters more in Arizona than people expect, because property taxes, homeowners insurance and any HOA dues all eat into the same house payment budget. Our post on how much house you can afford in Arizona walks through the full payment, and our debt to income ratio guide shows the math on every kind of debt, not just cars.

Should you pay off the car first?

Sometimes, but not by draining the cash you need to close. The right answer depends on how many payments are left and how much cash you have.

• If you are close to ten payments left, you may not need to do anything. Fannie Mae lets an installment loan with ten or fewer payments drop out of the ratio. Timing your application a few months out can do the work for free.
• If you have extra cash beyond your down payment, closing costs and reserves, paying the car down to ten or fewer payments can help. Fannie Mae's B3-6-07 says loans paid down that far generally do not need to be counted. It also says a payoff or paydown done only to qualify has to be carefully evaluated, and your history of using credit is part of that. Do not do it on your own. Let your lender decide whether it moves the needle first.
• If paying it off would empty your savings, keep the car loan and keep your cash. A smaller house with money in the bank beats a bigger approval you cannot close on. Our cash to close guide shows how much you really need on closing day.

One more thing. Paying off a car loan does not always help your credit score, and closing an account can change how your history looks. If your score is right on a line, talk to us about it before you write the check. We can show you where those lines are on your own report.

Run your own numbers

Car leases and payments someone else makes

A lease is the one car debt that never drops off early. Fannie Mae counts lease payments as a monthly debt regardless of how many months are left, because a lease that ends usually turns into a new lease, a buyout or a new car. So a lease with three months left counts in full, while a car loan with three payments left usually does not.

If a parent or someone else has been making your car payment, that can help. Fannie Mae lets the lender leave the payment out of your ratio when you document the most recent 12 months of canceled checks or bank statements from the person paying, with no late payments. The person cannot be the seller or an agent in your deal. Payments made in cash or through an app with no clear record are hard to prove, so start a clean paper trail now if this is your plan.

Never buy a car before closing

If you remember one thing from this page, make it this. Do not buy or lease a car between your pre-approval and your closing. Fannie Mae's B3-6-02 requires a lender to re-underwrite your loan if new debt is discovered after the underwriting decision and it pushes your ratio past the allowed tolerance. If the new number goes above 50% on Desktop Underwriter, the loan is not eligible at all. And if the lender pulls a new credit report after that decision, the loan has to be re-underwritten no matter what.

I have watched this happen. A buyer's old car dies two weeks before closing, the dealer approves them in an hour, and suddenly the loan that was clear to close is back in underwriting. Sometimes it still closes. Sometimes it does not. Our list of what not to do before closing in Arizona puts the car at the top for a reason.

My game plan for a buyer with a car loan

1. Pull your numbers first. Know your gross monthly income, your car payment and exactly how many payments are left.
2. Get a real pre-approval. A lender who actually reads your credit will tell you exactly how much house the car is costing you. Our mortgage pre-approval page explains what that looks like.
3. Compare loan types. FHA and conventional do not handle every debt the same way. Our conventional loans and FHA loans pages show who each one fits.
4. Decide on payoff with your lender, not before. Paying it down, waiting a few months or leaving it alone can each be the right answer. Let the numbers pick.
5. Freeze big purchases until you have keys. No car, no furniture on credit, no new cards.
6. Shop with your real number. Once you know it, browse current homes on Arizona Luxury Property Search and send us anything you like so we can run the exact payment.

Carrying student loans too? Those are counted under their own rules, so bring the statements when we talk. Shopping somewhere more affordable to offset the car? Our Casa Grande first time buyer guide runs the numbers on one of the lowest priced cities in the metro. If you want to know who you would be working with, here is my page, and the first time home buyer Arizona hub has every guide we have written for first purchases.

Honest caveat: lenders can always be more conservative than Fannie Mae's minimum, and Fannie Mae says so in its own guide. One lender may count a car with eight payments left and another may not. That is one reason I like being a broker. If one lender's rules are costing you house, we can often find one whose rules do not.

Sources

• Fannie Mae Selling Guide B3-6-05, Monthly Debt Obligations (08/05/2026): installment debt with more than ten payments counts, fewer counts if it significantly affects ability to pay, lease payments count regardless of months remaining, debts paid by others excluded with 12 months of documentation, checked November 6, 2026
• Fannie Mae Selling Guide B3-6-07, Debts Paid Off At or Prior to Closing (04/05/2023): installment loans paid off or paid down to 10 or fewer payments generally not included, paydowns to qualify carefully evaluated, checked November 6, 2026
• Fannie Mae Selling Guide B3-6-02, Debt-to-Income Ratios (04/02/2025): 36% manual, up to 45% with Eligibility Matrix requirements, 50% DU, re-underwriting when new debt is discovered, checked November 6, 2026
• Consumer Financial Protection Bureau, What is a debt-to-income ratio? (last reviewed August 28, 2023), checked November 6, 2026
• Freddie Mac Primary Mortgage Market Survey, week of November 5, 2026 (30 year fixed 7.18%), checked November 6, 2026. Loan amounts per payment computed at 7.18% for 30 years, principal and interest only.

This article is general information from Pillar Mortgage Group, not a loan offer or a commitment to lend. Loan rules, rates and lender requirements change, and every loan is subject to credit approval. Pillar Mortgage Group, LLC, NMLS #2700076, Arizona License MB-2009671, Equal Housing Lender.

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