Most people preparing to buy a home make the same logical and costly mistake with debt paydown. They rank payoff by interest rate, targeting the highest-rate balances first.
It feels financially responsible, and it is, if your goal is minimizing interest paid over time. To maximize what a lender will approve you for, the right payoff order runs in the opposite direction from most personal finance advice.
Mortgage underwriting ignores interest rates and measures monthly payment obligations instead. Paying off the account with the biggest payment and smallest balance first moves your debt-to-income ratio faster than any other sequence. A 12- to 18-month preparation window gives you enough runway to make this approach work before you apply.
Why the Debt Avalanche Method Works Against Homebuyers
The debt avalanche, paying the highest interest first, is the right strategy for long-term financial efficiency. Mortgage underwriting does not care about interest rates. It cares about monthly payment obligations. Your debt-to-income ratio (DTI) divides your total monthly debt payments by your gross monthly income.
A credit card with a $5,000 balance at 24% interest might carry a $150 minimum payment. A car loan with a $12,000 balance at 6% interest might carry a $450 payment. Under the avalanche method, you pay off the credit card balance first. Under a mortgage-optimization strategy, you prioritize the car loan.
Lenders see payments, not interest rates. Every dollar you eliminate from your monthly obligation column increases the mortgage payment you can qualify for and raises your purchasing ceiling. This distinction rarely appears in personal finance content. It shows up in conversations with mortgage advisors who run real numbers every day.
The Right Debt Payoff Sequence for Homebuyers
The framework centers on eliminating debt that moves the needle on buying power the fastest. You aren’t working to reduce the total amount of interest paid over tim
“If our number one goal is to increase your buying power, then our first step is to pay off debt that’s got the biggest payment and the smallest balance. We want to find the biggest payments first, and then sort those based off the smallest balance. So we knock one off, go to the next one, and go to the next one. That’s the plan of attack if our sole focus is buying power.” – Tevis Durbin, Producing Branch Manager (NMLS #424899)
This approach works because it targets accounts you can eliminate the fastest. Closing a $3,000 car loan with a $400 payment does more for your DTI than paying $3,000 toward a large credit card balance. With the car loan, the payment disappears entirely when the balance hits zero.
Partial paydowns rarely change minimum payment obligations enough to matter in underwriting. That is the part most buyers miss, and it is the part that costs them the most.
How Auto Debt Is Quietly Killing Mortgage Deals Right Now
Auto debt has reached a breaking point for many buyers. The 84-month car loan has become standard at dealerships. That extended term keeps monthly payments manageable on the surface, but it creates two problems for future homebuyers. Buyers stay underwater on the vehicle for far longer. And the payment still counts fully against the debt-to-income ratio regardless of how the loan was structured.
Monthly car payments of $800, $1,000, or even $1,500 are common now. These aren’t for luxury vehicles, but for everyday SUVs financed over seven years.
Consider a buyer carrying a $600 personal car payment plus a $300 co-signed loan obligation. That $900 combined figure can eliminate their purchase or force them much lower on the price point. The hit sometimes reaches $50,000 to $80,000 in purchasing power.
A car payment on your balance sheet deserves serious scrutiny 12 to 18 months before you plan to buy. Selling the vehicle for a cheaper option or eliminating the payment creates more buying power than almost any other move. You can learn more in our recent post about how auto loans interact with mortgage approval.
How to Build Your 12- to 18-Month Payoff Plan
A buyer who comes in with a year or more of runway gets a sequenced payoff plan rather than generic advice to pay down debt. The exercise works in four steps.
- List every monthly debt obligation. That includes auto loans, student loans, personal loans, credit card minimums, and co-signed accounts.
- Sort all the loans by monthly payment obligation. List them from largest to smallest.
- Within each payment tier, sort by current balance. Go from the smallest balance to the largest.
- Direct available extra funds toward the top of that list. When an account reaches zero, redirect its payment toward the next target.
Each eliminated payment frees up cash for the next target, and each improves your qualifying ratio in real time. A buyer who starts this process 18 months out often arrives at underwriting with a DTI profile that looks nothing like the one they started with.
Student loans deserve one important note. Deferment does not remove them from underwriting. Under Fannie Mae guidelines, most Qualified Mortgage programs count either 0.5% or 1% of the outstanding balance as an assumed monthly payment. That holds even when no payment is currently due.
An income-based repayment plan with a documented $0 payment is treated differently under some programs. Confirm which calculation applies to your loan type early, since the number used can meaningfully affect your DTI.
The Hidden DTI Variable That Surprises Buyers at the Finish Line
As you build your payoff sequence, flag one additional variable that consistently catches buyers off guard near closing. That variable is homeowners’ insurance. Underwriters now use roughly $700 per month per $100,000 of loan value as a planning benchmark for insurance costs in Indiana.
Actual premiums vary based on claims history, credit score, and property characteristics. A DTI running close to the qualifying limit leaves you exposed. An insurance quote higher than projected can compress your approval at the worst possible moment. The solution is to get insurance quotes earlier than necessary.
A tight DTI means treating insurance as another payment variable to model alongside your debt payoff plan, rather than a box to check at closing. The CFPB’s mortgage closing checklist helps you understand the cost variables underwriters consider at the final stage.
Common Questions About Debt Payoff and Mortgage Approval
Does paying off debt actually change my mortgage approval amount?
Yes, directly and measurably. Your debt-to-income ratio determines the maximum monthly payment a lender will approve. Every monthly debt obligation you eliminate increases the room available for a mortgage payment, which translates to a higher purchase price ceiling. The relationship is mathematical, not discretionary. Even eliminating one mid-size payment can shift your approved range by $30,000 to $50,000, depending on your income.
What counts as a monthly debt obligation in mortgage underwriting?
Auto loans, student loans, personal loans, minimum credit card payments, and co-signed accounts all count. Utilities, subscriptions, and insurance are generally excluded. Lenders pull your credit report and calculate DTI based on what appears there, so the picture is consistent across lenders using the same data. If something shows up on your credit report as a payment obligation, assume it counts until you confirm otherwise.
Should I close credit card accounts after I pay them off?
Not necessarily. Closing accounts can shorten your average credit history and increase your credit utilization ratio, both of which can lower your credit score. In most cases, paying the balance to zero and leaving the account open is the better move for your mortgage profile. Review your situation with your lender before making any changes. The mortgage application process is the wrong time to discover your credit score dropped unexpectedly.
My student loans are in deferment. Do they still count against my DTI?
Yes. Most loan programs require lenders to count either 0.5% or 1% of the outstanding balance as a monthly payment. That applies even when no payment is currently due. An income-based repayment plan with documented $0 payments may let some programs use that figure instead. On a $100,000 student loan balance, the gap between 0.5% and 1% is $500 per month in counted obligation. That number materially changes what you qualify for.
What if I have a co-signed loan for someone else?
It counts against your DTI regardless of who makes the payments. Some lenders allow an exclusion when the primary borrower has 12 months of documented on-time payments. Proper documentation is required. Address this early in your preparation window, because resolving it takes time and the documentation requirements are specific.
Is it better to pay down debt or save for a larger down payment?
It depends on your situation. Eliminating a high-payment debt sometimes qualifies you for a significantly higher purchase price. That makes the payoff more valuable dollar-for-dollar than additional down payment funds. In other scenarios, a larger down payment eliminates the need for mortgage insurance and improves your rate tier. Run both scenarios with your numbers before deciding. Indiana buyers also have access to down payment assistance programs many buyers overlook, which can change this calculation entirely.
How early should I start working on my mortgage strategy?
The 12- to 18-month window is ideal. It gives your advisory team time to map your payoff sequence, monitor credit changes as accounts close, and run updated scenarios as your numbers improve. Buyers who wait until 60 or 90 days before closing have far fewer options. Starting early means you arrive with momentum, not constraints.
Can I qualify for a mortgage if my DTI is above the standard limit?
Some loan programs allow higher DTI thresholds when accompanied by compensating factors. Strong reserves, a higher credit score, or a larger down payment can push lenders past the standard DTI ceiling in conventional programs. FHA loans have historically allowed higher ratios in certain cases. Non-QM programs exist for borrowers whose income structures or debt loads fall outside standard guidelines. The key is understanding which programs apply before assuming you are disqualified.
Buying Power Is Something You Build
Your buying power is not fixed. It is the result of decisions you make in the months before you ever tour a home.
A deliberate debt payoff strategy can meaningfully expand what you qualify for. It can get you into the home you actually want rather than the one that barely fits the math.
Ready to map out your plan? You can reach out to the Durbin Team at Supreme Lending to develop a strategy tailored to your timeline and finances.
Tevis Durbin is the producing branch manager of Supreme Lending. He holds a Certified Mortgage Advisor (CMA) designation, an MBA in Finance, and serves on the State Board for the Mortgage Bankers of Indiana. His team carries a 97.75% five-star client rating built on transparency, education, and a consistent advisory approach across branches in Fishers and Elkhart.
ABOUT THE AUTHOR
Tevis Durbin (NMLS #424899) is a Producing Branch Manager at Supreme Lending with over 26 years of experience in the mortgage industry. Leading “The Durbin Team,” Tevis combines his deep financial background – holding an MBA in Finance and a degree in Economics – with specialized loan programs to help Midwest homebuyers navigate complex markets. He is a Certified Mortgage Advisor, serves on the State Board for the Mortgage Bankers of Indiana, and acts as the Communication Chair for the Hamilton County division of MIBOR.