To buy and sell a house at the same time, you line up two contracts so the sale of your current home funds the purchase of the next one, use contingency clauses to keep either deal from collapsing the other, and bridge any timing gap with short-term financing or a rent-back. Most people aim for a same-day closing where the proceeds from the sale wire directly into the purchase.
Figure Out Your Equity and Qualify for Two Mortgages
Start with the math. Take your current home’s expected sale price, subtract the remaining mortgage balance, then subtract seller transaction costs of roughly 7% to 9% of the sale price once you combine agent commissions and closing fees. What’s left is the equity available for your next down payment.
Then budget for the buy side separately. Buyer closing costs generally run 2% to 5% of the purchase price and cover lender origination, title insurance, appraisal, prepaid property taxes, and insurance escrow. Smaller loans carry a higher percentage, larger loans a lower one.1Urban Institute. What Components Make Up Closing Costs
The qualifying problem comes next. When you apply for the new mortgage, lenders count both mortgage payments toward your debt-to-income ratio if you still own the first home. Ask your lender for a conditional pre-approval letter stating that the new loan will fund once the existing mortgage is paid off at closing. That letter tells sellers you’re qualified even though you currently carry a mortgage, and it’s often the piece that makes a simultaneous buy workable.
Decide Which Deal to Lead With
Your local market decides the order. In a seller’s market, generally defined by fewer than five or six months of available inventory, homes move fast. You can start shopping for the next home before listing the current one without much risk of being stuck with two mortgages.
In a buyer’s market, inventory sits. List first, wait for a signed contract, and only then commit to a purchase. A comparative market analysis from a local agent gives you realistic pricing on both ends and tells you which transaction is likely to be the harder one — that’s the one to start.
Contract Contingencies That Tie the Two Deals Together
Three contingency clauses handle most simultaneous buy-and-sell situations. Each one reduces the risk of owning two homes at once or losing your earnest money deposit, which is the good-faith payment of roughly 1% to 3% of the purchase price that goes in with your offer.
Home Sale Contingency
A home sale contingency makes your purchase conditional on selling your current home within a set period, often 30 to 60 days. Miss the deadline and you can walk away from the purchase with your earnest money. It’s the broadest protection, but it also weakens your offer, especially in competitive markets where other buyers are writing non-contingent terms.
Settlement Contingency
A settlement contingency applies when your current home is already under contract but hasn’t closed. Your new purchase depends on that pending sale actually going through. If the buyer backs out over inspection or financing, you can exit the new purchase without penalty. Sellers tend to accept this more readily than a general home sale clause because the sale is already lined up.
Kick-Out Clause
Sellers often counter a contingent offer with a kick-out clause. They keep marketing the home, and if a non-contingent offer comes in, you typically have 72 hours to either remove your contingency and commit, or walk away. Know in advance whether you can proceed without your old home being sold, because the clock moves fast.
Whichever contingency you use, the contract should spell out specific deadlines, the address of the property being sold, and what happens when a deadline is missed — whether the contract terminates automatically and whether the deposit is returned. Vague language leaves both parties exposed if a deal falls apart.
Financing to Cover the Gap
When contingencies and timing aren’t enough, a few financing tools let you move forward on the purchase before the sale closes.
Bridge Loan
A bridge loan is short-term financing against your current home’s equity. Terms typically run three to twelve months with interest rates in the 9% to 13% range, well above conventional mortgage rates. Lenders usually cap the combined loan-to-value ratio across both properties at 80%, so you need at least 20% equity between the two homes. The loan is paid off in full when the current home sells.
Home Equity Line of Credit
A HELOC lets you borrow against your current home’s appraised value, drawing only what you need and paying interest only on what you draw. The timing catch: apply well before listing. Lenders are reluctant to open new credit lines on a property already on the market, because an active listing signals the collateral is about to change hands. Line this up several months ahead if you want it available.
401(k) Loan
You can borrow from your 401(k) without a credit check. Federal rules allow up to 50% of your vested balance, capped at $50,000. Normal repayment runs five years with at least quarterly payments, but when the loan funds the purchase of a primary residence, the five-year deadline doesn’t apply and your plan may permit a longer window.2Internal Revenue Service. Retirement Topics Loans
Miss the repayment schedule and the outstanding balance is treated as a taxable distribution. You’ll owe income tax, and if you’re under 59½, a 10% early withdrawal penalty on top.2Internal Revenue Service. Retirement Topics Loans Processing can take several weeks, so coordinate with your plan administrator early.
How a Same-Day Closing Actually Works
In a double closing, both transactions settle on the same day or within a day of each other. The buyer of your old home signs their documents, their lender wires the purchase funds to the settlement agent, those funds pay off your existing mortgage and cover your commissions and seller closing costs, and the net proceeds move into the escrow account for your new purchase. Your new lender simultaneously wires its loan funds to the same or a cooperating settlement agent. When both sets of funds land, both deals close and titles transfer.
The coordination is tight. All wires have to complete within the same business day’s banking hours. A late wire, a last-minute document correction, or a missing signature on one side will stall both closings.
A few practical steps keep the day on track:
- Use the same title company or settlement agent for both transactions when possible, so one team controls the flow of funds.
- Schedule the sale closing in the morning and the purchase closing in the afternoon, giving the proceeds time to transfer.
- Confirm wire instructions with all lenders at least 48 hours before closing day, and verify that both settlement agents have each other’s contact information.
Rent-Back if You Need Extra Days
A rent-back agreement, formally a post-settlement occupancy agreement, lets you stay in the old home for a short period after the sale closes. The buyer becomes your temporary landlord. The rate is usually based on the buyer’s mortgage costs (principal, interest, taxes, and insurance) or comparable local rents, and you’ll put down a security deposit the buyer holds until you vacate.
The agreement sets an exact move-out date, and the home should be empty and clean when you leave. Periods typically run a few days to a few weeks, though terms are negotiable. This is the fallback that keeps you from cramming a sale, a purchase, and a physical move into the same 24 hours.
Budget for Costs on Both Sides
Running two transactions means paying costs on two sides, and underestimating them is the most common financial mistake in a simultaneous move.
On the sale:
- Agent commissions historically around 5% to 6% of the sale price, split between listing and buyer agents.
- Seller closing costs of roughly 1% to 3% of the sale price, covering title fees, prorated taxes, and other settlement charges.
- Transfer taxes, which most states set between 0% and 3% of the sale price, with some states and municipalities charging nothing.
On the purchase:
- Buyer closing costs of 2% to 5% of the purchase price for lender fees, title insurance, appraisal, and escrow.1Urban Institute. What Components Make Up Closing Costs
- Per diem interest from your closing date through the end of the month, which is why many buyers aim for a late-month closing.
- A potential simultaneous-issue discount if you buy the lender’s and owner’s title policies from the same company.3Consumer Financial Protection Bureau. TRID Title Insurance Disclosures Factsheet
Combined costs across both deals can easily reach 10% to 14% of the combined property values. Build that into your equity math from the start, because it directly reduces what’s available for the next down payment.
Capital Gains on the Sale
Selling at a profit triggers federal capital gains rules, but most primary-residence sellers owe nothing. Single filers can exclude up to $250,000 of gain, and married couples filing jointly can exclude up to $500,000. You must have owned and used the home as your primary residence for at least two of the five years before the sale, and you can only claim the exclusion once every two years.4Office of the Law Revision Counsel. 26 USC 121 – Exclusion of Gain From Sale of Principal Residence
If you used the home as a rental or for business during part of your ownership, any gain tied to those non-residential periods won’t qualify.4Office of the Law Revision Counsel. 26 USC 121 – Exclusion of Gain From Sale of Principal Residence If you’re counting on the full sale proceeds to fund the next purchase, work through the tax picture early so you know how much cash actually reaches the closing table.