To buy and sell a house at the same time, you coordinate two contracts with linked contingencies, arrange short-term financing if you need to tap equity before your sale closes, and schedule both closings in close sequence — sometimes on the same day — so the proceeds from your sale fund the new purchase. Which side you lead with, and how much financial cushion you need, depends on your local market, your equity, and your tolerance for briefly carrying two mortgages.
Sort Out the Money Before You List or Shop
Start with net equity. Take your current home’s likely sale price, subtract what you still owe on the mortgage, then subtract seller transaction costs of roughly 7% to 9% of the sale price. What’s left is what you actually have for the next down payment.
Budget separately for buyer closing costs on the new home, generally 2% to 5% of the purchase price. Those cover lender origination fees, title insurance, the appraisal, prepaid property taxes, and homeowner’s insurance escrow. Closing costs take up a larger share of smaller loans and a smaller share of larger ones.1Urban Institute. What Components Make Up Closing Costs
Then talk to a lender about the debt-to-income problem. While you still owe on your current home, both mortgage payments count against your DTI, which can block a new approval. Ask for a conditional pre-approval letter stating the lender will fund the new mortgage once the existing one is paid off at closing. That letter tells sellers you’re qualified even though you currently carry a mortgage.
Decide Which Deal to Lead With
Your local market decides the order. In a seller’s market — generally fewer than five or six months of inventory — homes move quickly, and you can start shopping before you list without much risk of being stuck with two mortgages. In a buyer’s market, homes sit. Listing first and waiting for a signed contract before you commit to a purchase is safer. A comparative market analysis from a local agent gives you realistic pricing for both sides and helps you pick the lead.
Contingencies That Tie the Two Contracts Together
Contract contingencies are how you protect yourself from owning two houses or losing your earnest money — the good-faith deposit you submit with an offer, typically 1% to 3% of the purchase price.
Home Sale Contingency
A home sale contingency makes your purchase conditional on selling your current home within a set window, often 30 to 60 days. Miss the deadline and you can walk away with your earnest money. It’s the strongest protection, and also the least appealing to sellers, especially against non-contingent competition.
Settlement Contingency
A settlement contingency works when your current home is already under contract but hasn’t closed. If that sale falls apart over inspection or financing, you can exit the new purchase without penalty. Sellers usually view this as lower risk than a general sale contingency, since your buyer 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 get 72 hours to either drop your contingency and commit or walk. Be ready to decide quickly whether you can close on the new home without having sold the old one.
Whichever clause you use, spell out the deadline, the address of the property being sold, and what happens if a deadline is missed — automatic termination, deposit refund, or otherwise. Vague language leaves both sides exposed when a deal wobbles.
Financing to Bridge the Gap
If timing and contingencies aren’t enough, a few tools can front the money you need before your sale closes.
Bridge Loans
A bridge loan is short-term financing against your current home’s equity, usually three to twelve months, with interest rates in the 9% to 13% range — well above conventional mortgage rates. Lenders typically cap combined loan-to-value at 80% across both properties, so you need at least 20% equity between the two homes. You repay in full when the old home sells.
Home Equity Line of Credit
A HELOC lets you borrow against your current home’s appraised value and pay interest only on what you draw. The catch is timing: apply well before you list. Lenders are often unwilling to open a new credit line on a home that’s already on the market, since an active listing signals the collateral is about to change hands. Plan several months ahead if you want this option.
401(k) Loan
You can borrow from your 401(k) with no credit check. Federal rules let you take up to 50% of your vested balance, capped at $50,000, and repayment usually has to happen within five years with at least quarterly payments. When the loan is used to buy a primary residence, the five-year limit doesn’t apply, and your plan may allow 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 on it, and if you’re under 59½, potentially a 10% early withdrawal penalty as well.2Internal Revenue Service. Retirement Topics Loans Loop in your plan administrator early; processing can take weeks.
What Both Deals Will Cost You
Running two transactions means paying costs on both sides, and underestimating them is one of the more common mistakes here.
On the seller side:
- Agent commissions, historically around 5% to 6% of the sale price split between the listing agent and buyer’s agent. After the 2024 changes to how buyer agent compensation is negotiated, sellers are no longer required to offer that compensation through the MLS, though many still do.
- Seller closing costs, typically 1% to 3% of the sale price, covering title fees, prorated property taxes, and other settlement charges.
- Transfer taxes, ranging from 0% to about 3% depending on state and municipality.
On the buyer side:
- Buyer closing costs, generally 2% to 5% of the purchase price.1Urban Institute. What Components Make Up Closing Costs
- Per diem interest for the days between your closing date and the end of the month. Closing near month-end reduces this charge.
- A potential simultaneous-issue discount when you buy the lender’s and owner’s title insurance policies from the same company.3Consumer Financial Protection Bureau. TRID Title Insurance Disclosures Factsheet
Combined, transaction costs across both deals can easily reach 10% to 14% of the combined property values. Build that into your equity math from the start.
How a Same-Day Closing Actually Runs
In a simultaneous closing, both transactions are scheduled on the same day or within a day of each other. The buyer of your old home signs first and their lender wires the purchase funds to the settlement agent. Those funds pay off your existing mortgage, cover commissions and seller closing costs, and the net proceeds move into escrow for your new purchase. Your new lender wires its loan funds to the same or a cooperating settlement agent. Once both sets of funds arrive, both deals close and titles transfer.
The whole thing depends on tight coordination between the escrow officers or real estate attorneys on each side. Every wire has to clear within one business day’s banking hours. A late wire, a document correction, or a missing signature can stall both closings.
To lower the timing risk:
- Use the same title company or settlement agent for both transactions when you can, so one team controls the flow of funds.
- Schedule the sale closing in the morning and the purchase closing in the afternoon.
- Confirm wire instructions with every lender at least 48 hours before closing day, and make sure both settlement agents have each other’s contact information.
Rent-Back for a Softer Landing
A rent-back agreement, formally a post-settlement occupancy agreement, lets you stay in your old home for a short period after it sells. The buyer becomes your temporary landlord. The rate is usually pegged to the buyer’s principal, interest, taxes, and insurance, or to comparable local rents, and you put down a security deposit. The agreement fixes an exact move-out date, at which point you’re expected to leave the home empty and clean. Rent-back periods typically run a few days to a few weeks. It gives you room to close on the new place and handle the move without stacking everything onto one day.
If you’re on the other side of a rent-back — you just bought a home whose seller is staying briefly — keep your homeowner’s insurance active from the day of closing, and have the seller carry renter’s insurance for the occupancy period.
Capital Gains When You Sell
Federal tax law lets you exclude a large share of the gain on the sale of a primary residence. Single filers can exclude up to $250,000, married couples filing jointly 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 your gain exceeds the exclusion or you don’t meet the ownership and use tests, the closing agent reports the sale to the IRS on Form 1099-S, and you report the taxable portion on your federal return. If the gain fits within the exclusion, the closing agent can skip Form 1099-S as long as you provide written certification that the full gain is excludable and the home was your primary residence.5IRS.gov. Instructions for Form 1099-S Proceeds From Real Estate Transactions
If part of your ownership period involved renting the home out or using it for business, gain tied to those non-residential periods doesn’t qualify.4Office of the Law Revision Counsel. 26 USC 121 – Exclusion of Gain From Sale of Principal Residence Work that into your planning early if you’re counting on the full sale proceeds to fund the next purchase.