A home sale contingency is one of the most emotionally loaded provisions in a purchase agreement. For buyers, it's a lifeline — they need the proceeds from their current home to close the new one, and without the contingency, they're exposed. For sellers, it's a red flag — they're being asked to park their home for a buyer whose ability to perform depends entirely on a third transaction they have zero visibility into.
Both perspectives are valid. And if you're going to advise clients on either side of a contingent deal, you need to understand the mechanics well enough to set realistic expectations — before the offer goes in, not after something goes sideways.
Here's what you need to know: how to write one correctly, how the kick-out clause works in practice, and when a contingency does more harm than good.
What a home sale contingency actually says
A home sale contingency makes the purchase of the new property conditional on the buyer successfully closing on their existing home by a specific date. Most forms include two separate fields: a sale date (by which the buyer's current home must be under contract) and a settlement date (by which that sale must close). Both need to be filled in — and both need to be realistic. An overly compressed timeline can give a seller grounds to reject your buyer's financing as inadequate, or put your buyer in a position where they can't actually perform. Miss either field and you've created ambiguity about what "sold" actually means, which is not a fight you want to have at the closing table.
Why sellers resist them — and why that resistance is rational
When a seller accepts a contingent offer, they're effectively taking their home off the market for a buyer who hasn't yet proven they can sell their current property. If the buyer's home sits unsold, gets a bad appraisal, or falls out of contract, the seller is stuck waiting — while serious non-contingent buyers may have moved on. This isn't irrational stubbornness on the seller's part. It's a genuine transfer of risk from buyer to seller. Understanding that helps you negotiate more effectively and set realistic expectations for your buyer before the offer even goes in.
The kick-out clause — the seller's most common counter-move
The standard seller response to a home sale contingency is a kick-out clause — sometimes called a "72-hour clause" or "first right of refusal." A kick-out lets the seller keep marketing the property. If another offer comes in, they notify the contingent buyer in writing, giving them a defined window — typically 24 to 72 hours — to either remove the contingency and proceed, or release the seller to accept the new offer. Buyers who can't remove the contingency in time get kicked out. Your buyer needs to fully understand the kick-out mechanics before they sign — not after the notice lands in their inbox at 4pm on a Friday.
How the 72-hour clock actually works
Here's where agents get tripped up: the kick-out clock starts the moment the seller's agent delivers written notification — not when your buyer reads it, not when you return the call. This is why your client needs to be on standby from the day a contingent offer is accepted. Walk through the worst-case scenario before you submit: if a kick-out notice arrives Thursday afternoon, what's the exact deadline? Who needs to sign off to remove the contingency? Does your buyer have bridge financing or enough liquid assets to proceed without their sale proceeds? These decisions need to be made before the offer is submitted — not during the 72-hour scramble while another buyer waits in the wings.
How to write one that actually holds up
Three things make a home sale contingency defensible: a realistic sale date that gives your buyer's existing listing time to go under contract; a close date that allows both transactions to settle without requiring a true simultaneous close (unless that's explicitly planned and funded); and a clear definition of what "sold" means — typically a fully executed purchase agreement on the existing property. Some forms require the buyer to list their home within a set number of days of acceptance. If that provision is present, make sure your buyer can actually meet it. An open-ended contingency with no listing requirement is cleaner than one with obligations your buyer can't keep.
When to tell your buyer to skip it entirely
Sometimes the most valuable advice you can give is to not use the contingency at all. If your buyer's existing home is already under contract and within 30 days of closing, a home sale contingency is probably unnecessary — and removing it makes the offer significantly cleaner. If your buyer has bridge financing or enough assets to carry both properties temporarily, a contingent offer may be the wrong tool altogether. In a competitive listing with multiple strong offers, a contingent offer almost always loses. Know your buyer's actual financial position before defaulting to the contingency. It's a protection device, not a requirement — and treating it like one costs buyers deals they could have won.
The most dangerous moment in a contingent deal
It's not when the kick-out notice arrives. It's before the offer is even accepted — when nobody has asked the hard questions yet.
Does your buyer's existing home need work before it can list? Is their expected list price realistic for a 30-day close? Are they pre-approved on the new purchase without counting on the sale proceeds to hit their down payment? A home sale contingency that papers over a buyer who isn't actually ready to move doesn't protect anyone — it just delays the problem until the worst possible moment. Do the underwriting before you write the contingency.