How a Lender Counts Your Existing Mortgage Payment on a Conventional Loan

The Quick Read: A lender counts the payment on any mortgage you will still owe after closing, and that payment goes into your debt-to-income ratio. A mortgage that gets paid off at closing drops out. If you keep the old home, both payments usually count. The main exception is a documented sale of the old home.

Debt-to-income ratio (DTI) is your total monthly debt payments divided by your stable monthly income. It is the number that decides how much house a lender can approve you for. This article walks through how the existing payment gets classified, which paperwork moves it in or out, and where the rule bends.

Key Terms Defined

DTI (debt-to-income ratio): Your monthly housing payment plus other monthly debts, divided by your stable monthly income.

PITIA: Principal, interest, taxes, insurance, and assessments such as HOA dues. It is the full monthly cost of owning a property.

Contingency: A condition in a sales contract, such as the buyer getting a loan, that must clear before the sale is firm.

Departing residence: The home you live in now and are leaving, whether you sell it or keep it.

DU (Desktop Underwriter): Fannie Mae’s automated system that reviews a loan file and returns a finding.

Seasoning: How long a loan or ownership has existed before a new transaction can use it.

What Counts, and What Doesn’t

Every mortgage you will still owe after closing counts. Every mortgage that gets paid off at the closing table does not. That one question, “does this loan survive closing?”, drives most of the answer.

The agencies back this up. Fannie Mae’s Selling Guide on other real estate owned says the property’s status determines how its PITIA is counted when you qualify for the new loan. The same section says the PITIA of an existing second home counts as a recurring monthly debt. For your own principal residence, Fannie Mae’s monthly debt obligations section says the housing payment must be considered when underwriting.

“Payment” means the whole PITIA, not just principal and interest. Taxes, insurance, and association dues on the old home are part of the number, even if they are paid outside the mortgage.

The Quick-Reference Table

Treat the table as the general pattern. Agency rules differ at the edges, and individual lenders can add their own requirements.

How Does a Lender Work This Out, Step by Step?

The lender follows a fixed sequence. You can predict most of it from the order.

1. You list everything. Every property and mortgage goes on the loan application. Freddie Mac’s Guide section on liabilities requires liabilities to appear on the Uniform Residential Loan Application and be considered in qualifying.

2. The lender verifies. The credit report usually shows your mortgage payment. If a housing payment is not documented there, the lender has to document it another way.

3. Each mortgage gets sorted. It lands in one of three buckets: paid off at closing, kept, or tied to a home that is being sold.

4. The lender does the math. The new payment is added to the other counted debts. Installment loans, like car loans, count when more than ten monthly payments remain. Freddie Mac uses the same ten-payment test, including debts in deferment or forbearance. The total is divided by your qualifying income.

5. The lender re-checks before closing. A new debt or a changed payment can force a re-run. On Fannie Mae loans, if recalculated DTI goes above 45% on a manually underwritten loan, or 50% on a DU loan, the loan is not eligible for delivery to Fannie Mae.

Where the Ceiling Sits

The numeric DTI limits come from Fannie Mae and Freddie Mac, not from a federal consumer rule. Across the wholesale programs we place conventional files with, the automated finding governs most files, with a total ratio ceiling of 50%. Manually underwritten loans run at 36%, or up to 45% when the file meets the credit score and reserve factors in the Eligibility Matrix.

Those are ceilings, not promises. A strong score, solid reserves, and stable income can give you more room. Thin reserves and a high ratio together typically do not.

On the credit side, the wholesale conventional programs we work with start at a 620 decision score, and 640 on an adjustable rate under manual underwriting. All figures are subject to lender guidelines and full file review.

Buying Before You Sell: The Exception That Matters Most

If your old home hasn’t closed when the new loan does, the default is that both payments count. Fannie Mae’s rule is that the current PITIA and the proposed PITIA must both be used in qualifying when the sale will not close before the new loan does.

The exception: Fannie Mae won’t require the current residence’s PITIA if the file has the executed sales contract and confirmation that any financing contingencies have been cleared. Freddie Mac’s version is close. The payment on the property pending sale may be excluded with an executed contract, and if that contract has a financing contingency, the file must also show the contingency was cleared or contain the buyer’s lender commitment. Freddie Mac also has an employee-relocation variant with its own requirements.

The paperwork checklist

For the old payment to drop out, the lender generally needs:

• A fully executed sales contract for the old home.
• Proof that any financing contingency has cleared, or the buyer’s lender commitment.
• The documents in the file before closing, not promised afterward.

Timing matters. A contract that arrives after your application still helps, as long as it is in the file in time. A contingency that clears late, or a sale that falls apart, can put the old payment back into your DTI. Tell your loan officer the moment anything changes.

What Doesn’t Count as an Exception

These are the common misreadings:

• “My home is listed.” A listing is not a contract.
• “I have a buyer.” A verbal buyer is not an executed contract.
• “My buyer is under contract.” Not enough if the buyer’s financing contingency is still open.
• “I plan to sell right after closing.” Intentions do not change the debt.

Each of these keeps the old payment in your ratio. Wait for the documents, not the promise.

Keeping the Old Home as a Rental

If you keep the old home, the full payment counts unless rental income offsets it. Rental income is not applied automatically. It follows its own rules, and a negative result lands in your DTI.

Fannie Mae’s rental guidance covers this departing-residence case. Under the version in a recent Fannie Mae supplement, the lender takes 75% of the gross rent, subtracts the old home’s PITIA, and uses the rent only if the result is positive. Fannie Mae has changed how a departing residence’s rent can be documented, including the role of a lease and an appraiser-completed rent schedule, so ask your loan officer which method applies to your file today. The appraisal enters the picture only here. For the payment itself, the appraisal does nothing, because it values the property rather than deciding how the payment is treated.

Two more cautions. Keeping the old home can trigger reserve requirements. Fannie Mae’s guide points to minimum reserve rules and multiple-financed-property policies. And Fannie Mae’s occupancy-fraud guidance lists converting a current owner-occupied residence to a rental as a red flag lenders investigate. The new home must be a real primary residence for you. Final terms depend on the lender’s guidelines, the property type, and the borrower’s complete credit picture.

A principal residence can go to 95% LTV on a standard purchase, and second homes top out at 90%. Each figure is subject to lender guidelines and a complete review of property type, leverage, and credit.

Other Edge Cases

Someone else pays your mortgage. Fannie Mae’s FAQ allows the payment to be excluded only if the paying party is obligated on the mortgage, there are no delinquencies in the most recent 12 months, and you aren’t using rental income from that property to qualify. The lender also needs 12 months of canceled checks or bank statements from the other party.

Bridge or swing loans. A bridge loan creates a contingent liability that counts in DTI. Fannie Mae waives this when the file has a fully executed sales contract for the current residence and confirmation that financing contingencies have cleared.

Assumed mortgage. If someone is assuming your mortgage, the lender does not have to count the contingent payment when it verifies the purchaser has at least a 12-month history of regular, timely payments.

HELOC. A home equity line of credit counts if it requires a monthly payment. If it requires none, there is nothing recurring to count under Fannie Mae.

Special refinance products. Some limited and high-LTV refinance products carry their own DTI rules. Ask which program your file falls under.

One Household, Three Outcomes

Picture a buyer with a comfortable income who is moving up to a larger home with 5% down. Her old home carries a mortgage, and she wants to buy first. Here is how the old payment behaves in three versions of the same story. The percentages below are modeled assumptions, not market data. Leverage, reserves, and pricing vary by lender and program; the final terms follow the full file review.

With both payments counted, her DTI can climb toward the 50% automated ceiling and may exceed it. With the old payment excluded, her ratio could fall well inside it. With rent offsetting part of the old payment, she lands in the middle, and only the shortfall is counted. Same house, same income, three very different files. The paperwork decides which one she gets.

What to Do Before You Apply

• List every property and mortgage. Do not leave anything for the lender to find.
• Decide your sequence early. Selling first, buying first, and coordinating closings each change which bucket you are in.
• Gather the sale documents. Get the executed contract and proof of cleared contingencies into the file as soon as they exist.
• Avoid new debt. A new car loan or credit line during the process can force re-underwriting.
• Know your payoffs. Non-mortgage installment loans paid down to ten or fewer remaining payments can be left out of DTI. That relief does not apply to your existing home mortgage unless it is itself paid off.
• Watch your payment history. Late payments matter separately from the payment amount. Fannie Mae treats an excessive prior mortgage delinquency as a 60-, 90-, 120- or 150-day late on any mortgage tradeline in the 12 months before the credit report date, and those loans are not eligible for delivery.

If you are refinancing rather than buying, remember that the loan being paid off comes out of the picture. On a cash-out refinance, the first mortgage being paid off must be at least 12 months old, measured note date to note date, and a borrower must have been on title for 6 months, with exceptions for delayed financing, inheritance, and legal awards.

A Practitioner’s Note

In the files that come across a broker’s desk, the surprise is rarely the rule. It is the paperwork gap. A buyer says the old home is “basically sold,” and the file has a contract with an open contingency. The ratio that looked fine on a napkin does not clear once the old payment is counted. Lining up the documents before you write an offer is far cheaper than discovering the gap at the end.

You can read more about how a lender evaluates a file when you already own a mortgage in Lendmire’s article Can You Qualify for a Conventional Loan With an Existing Mortgage?. If your plan includes help with the down payment, Lendmire’s piece How to Use Down Payment Assistance With a Conventional First Mortgage covers how that fits alongside your first loan.

For the basics of how these loans are built, see Lendmire’s conventional loan programs page.

If you are buying a home and want to see whether a conventional loan fits your file, Lendmire can help you compare the options and what each one asks of the file. Rules differ between Fannie Mae, Freddie Mac, and individual lenders, so confirm the details for your situation. Nothing here is a commitment to lend.

For your own numbers, request a scenario review with Lendmire.

About Lendmire

As a mortgage broker (NMLS# 2371349), Lendmire helps homeowners and home buyers in 16 states with FHA, VA, conventional and jumbo purchase and refinance loans arranged through wholesale lenders. Lendmire is never the lender; program terms are set by the lender and the agency guidelines. Scotsman Guide named Lendmire a Top Mortgage Workplace in both 2025 and 2026.

References

1. Fannie Mae Selling Guide B3-6-06: Qualifying Impact of Other Real Estate Owned

2. Fannie Mae Selling Guide B3-6-05: Monthly Debt Obligations

3. Freddie Mac Guide Section 5401.2

4. Fannie Mae’s rental guidance

5. Fannie Mae occupancy-fraud guidance

6. Fannie Mae top trending Selling FAQs