Selling and buying a house at the same time: debt rules

What does the lender check?

Lenders compare your monthly debts with your income, a number called the debt-to-income ratio. See debt-to-income ratio for the basics. Owning two homes during the overlap can double the housing part of that ratio, which is why the order of closings matters.

Fannie Mae’s rule is for loans that follow its Selling Guide, which covers most conventional loans. Other loan types have their own handbooks, so ask your lender which one applies. The guide pages read for this article are B3-6-06 (other real estate owned) and B3-6-05 (monthly debt obligations).

What happens if my old home closes first?

Then the old payment ends before the new loan starts, and the pending-sale rule does not apply. The tradeoff is practical, not financial: you may need a place to live between closings. A later possession date is a point you can negotiate in the sales contract; no official source sets it.

What if my old home closes after the new loan?

The Selling Guide covers this as a pending sale. Quoted from the guide, the rule applies when the sale “will not close (with title transfer to the new owner) prior to the subject transaction.” In that case, both the current payment and the proposed payment (PITIA) must be used to qualify you for the new loan. PITIA means principal, interest, taxes, insurance and association dues.

Fannie Mae will not require the current residence’s payment to be counted if the lender provides:

1. the executed sales contract for the current residence, and
2. confirmation that any financing contingencies have been cleared.

If either document is missing, plan on being qualified with two payments.

What is a sale contingency?

A sale contingency is a clause in a purchase contract that makes the deal depend on an event, in this case the sale of the buyer’s current home. It is a contract term, not a federal rule, so the parties negotiate it. Do not confuse it with the financing contingencies in Fannie Mae’s rule: those are conditions in the contract for your buyer’s loan. When your old home is under contract with those cleared, your new lender can drop your old payment from the numbers.

What are my short-term financing options?

You can use savings or other funds, a loan against your current home’s equity or a bridge loan. See bridge loans and home equity loans and HELOCs. For Fannie Mae loans, the Selling Guide says a bridge loan creates a contingent liability that counts in your monthly debts and in the debt-to-income ratio, unless the same two documents above are provided.

Federal ability-to-repay rules do not cover some of these loans. 12 CFR 1026.43(a)(3)(ii) exempts a temporary or bridge loan with a term of 12 months or less, for example a loan to buy a new home when the consumer plans to sell a current one within 12 months, from the ability-to-repay requirements in paragraphs (c) through (f).

What if I keep the old home?

If you keep your old principal residence as a second home, the guide says its housing payment must also be counted in your recurring monthly debts. If it becomes an investment property, you must be qualified under the rental income rules in the Selling Guide (B3-3.8-05 covers departing residences). The rules differ, so ask your lender early.

A simple illustration

This example is hypothetical. Suppose your old mortgage payment (PITIA) is $2,000 a month and your new one will be $2,800. If your old home will not close before the new loan and the lender does not have the two documents, the lender counts $4,800 of housing payments against your income. If it has the signed contract and cleared financing contingencies, it can count $2,800. The difference is $2,000 a month in the ratio, which can decide whether you qualify.

Do I owe tax on the old home?

The sale can produce a gain. For a main home, IRS Publication 523 (2025) lets you exclude up to $250,000 of gain, or $500,000 for a married couple filing jointly, if you meet the ownership and use tests. Subtract selling expenses from the price first. See capital gains on a home sale and the cost of selling a house.

Where states differ

The lender rules above are federal-market rules and do not change by state. States decide the closing process, attorney involvement, transfer taxes and disclosures for both of your transactions. Use the transfer tax calculator, the closing costs calculator and the state tables, and check the home affordability calculator to test two payments.