By Eric Berman, REALTOR® | The Eric Berman Team at Compass
TL;DR:
The average Long Island home seller leaves $20,000 to $50,000 on the table at closing — and it's rarely the market or the agent's fault. It comes down to five things almost nobody explains before listing: treating an accepted offer as a done deal, ignoring the legal landmines hiding in your own yard, misreading what your STAR-reduced tax bill tells buyers, walking blindly into the $1 million mansion tax cliff, and following the oldest bad advice in real estate — "list high, you can always come down." Fix these before signing a listing agreement and you keep money that would otherwise disappear at the closing table.
Why I'm Writing This
If you're getting ready to sell in Nassau County, Suffolk County, or Northeast Queens, this is the conversation I have with sellers every single week — usually too late. The five mistakes below are the ones I see repeatedly costing real money at closing, and they're all preventable if you know what to look for before listing. The video above walks through everything in detail; this post is the written companion that goes deeper on each mistake and links to the resources I use with my own clients.
Mistake 1: Treating an "Accepted Offer" Like a Done Deal
In New York, "accepted offer" means far less than people think.
An accepted offer is not a binding contract. Nothing is locked in until both attorneys draft, redline, and fully execute the contract of sale — and that process usually takes one to three weeks. During that window, either side can walk away for any reason, or no reason at all.
That's where deals quietly fall apart. The buyer keeps shopping. A second inspection raises new questions. The attorney finds something in the title. Meanwhile the seller has mentally spent the money and stopped showing the house.
The fix is simple and most sellers skip it: line up a high-volume New York real estate attorney before you list, not after. When your attorney is ready to turn a contract around in days instead of weeks, you shrink the window where a deal can die. (Watch me break this down at 1:30.)
I walk every seller I work with through exactly what happens after you accept an offer on your Long Island home so the contract phase doesn't catch them off guard.
Mistake 2: The Landmines Hiding in Your Own Yard
The second mistake costs sellers real money about a week before closing — the worst possible time.
Two culprits show up again and again on Long Island: unpermitted work and underground oil tanks.
Unpermitted work — a finished basement, a deck, a dormer, an extension done without a closed permit — surfaces in the title search. When it does, the buyer's attorney asks for it to be resolved, and you're suddenly negotiating credits, chasing the building department for a certificate of occupancy, or watching the deal stall. I've seen this single issue cost sellers $30,000 to $50,000 in last-minute credits.
The underground oil tank is the one almost nobody warns you about. An abandoned or leaking tank buried in the yard is an environmental liability that can blow up a closing overnight — buyers and their lenders do not want to inherit it.
The move here is to get ahead of both. Pull your permit history and deal with open or missing permits before you list, not when a buyer's attorney forces the issue. If you have an old oil tank, document its status now. Here's the full playbook on how to sell a Long Island home with open permits or unpermitted work, and a look at how inspection negotiations actually work once issues come up.
Mistake 3: Your STAR Exemption Is Lying to You (and to Your Buyers)
Here's a quiet one that trips up sellers and torpedoes buyer financing.
STAR, Enhanced STAR, Senior Citizens, and Veterans exemptions all follow the person, not the property. They do not transfer to the buyer.
So if you've been paying $12,000 a year in taxes with Enhanced STAR, the home a buyer is actually purchasing might carry a real, post-sale tax burden closer to $18,000 to $20,000 once your exemptions come off. (Watch me explain this at 10:30.)
That gap matters for two reasons. First, the low tax number on your statement makes your home look cheaper to carry than it really is, which sets buyer expectations you can't deliver. Second — and this is the killer — the higher true tax figure gets baked into the buyer's mortgage math. It can push their debt-to-income ratio over the line and kill the loan after you're already in contract.
Price and market your home against its true, post-sale tax picture, not the exemption-reduced bill on your current statement. If you want context on where Nassau taxes are heading, read what the Nassau County property tax reassessment means for sellers.
Mistake 4: Walking Off the $1 Million Mansion Tax Cliff
The New York mansion tax is a cliff, not a slope — and that distinction is worth thousands.
The tax kicks in the moment a sale price hits $1 million, and it applies to the entire purchase price, not just the amount above the threshold.
Sell at $999,999 → the buyer owes $0 in mansion tax.
Sell at $1,000,000 → the buyer owes $10,000.
One extra dollar of price creates a $10,000 tax bill. That's why homes priced right at the edge of $1 million can sit — buyers feel the penalty and hesitate.
If your home is hovering near that line, pricing strategically just below $1 million often does the opposite of what sellers fear. It widens your buyer pool, draws more showings, and frequently generates competing offers that push the final number up anyway — without handing the buyer a $10,000 reason to walk. Here's the full breakdown of the NY mansion tax for Long Island sellers above $1M.
Mistake 5: "List High, You Can Always Come Down"
This is the oldest advice in real estate, and it's actively costing Long Island sellers money.
The thinking sounds reasonable: start high, leave room to negotiate, drop the price later if you have to. The problem is that the market has changed and buyers are more informed than ever.
A home gets the most attention in its first week or two on the market — that's when fresh listings hit every buyer's saved search and inbox. Overprice it and you waste that window on the wrong audience. By the time you cut the price, the listing looks stale, days-on-market piles up, and buyers start assuming something is wrong with the house. Price reductions invite lowball offers; they don't reset the clock.
Pricing correctly out of the gate does the heavy lifting overpricing promises but never delivers — it concentrates demand, creates urgency, and gives you leverage instead of taking it away. I've written more about this dynamic in the context of specific Long Island markets — how to choose the right listing price for a Manhasset home covers the aspirational pricing problem in detail, and the Levittown overpricing diagnostic walks through what happens when a listing has already gone wrong.
The Bottom Line: Have the Conversation Early
Every one of these mistakes is fixable — but only before you list. Once you're in contract, an unresolved permit, a buried oil tank, a misread tax bill, or a price set $1 over the mansion tax line stops being a strategy question and becomes a problem you're paying to solve.
The sellers who keep that $20,000 to $50,000 aren't smarter or luckier. They had the right conversation early, with someone who knew where the Long Island and Queens landmines are buried.
For a fuller walk-through of the whole seller process, the Long Island seller's checklist covers the broader arc from pre-listing through closing. The home valuation starting point is the quiet way to start the conversation if you're not yet sure when you'd list. And the broader Local Insights archive covers the rest of the seller-side content.
FAQs
What's the biggest mistake Long Island sellers make?
The biggest mistake is treating the marketing and pricing decisions as separate from the legal and financial preparation. Sellers spend time staging and photographing the home but skip the conversations that actually determine whether the deal closes cleanly — lining up an attorney before listing, resolving open permits, understanding how STAR exemptions affect buyer financing, and pricing strategically around the $1 million mansion tax cliff. Each of these issues quietly costs sellers real money at closing if they surface too late. The fix is treating the pre-listing window as the time to address all of them, not just the cosmetic preparation.
How long does it actually take to go from accepted offer to signed contract in New York?
Typically one to three weeks, sometimes longer for high-value or complex transactions. During that window, either side can walk away for any reason. The buyer's attorney and the seller's attorney draft, redline, and finalize the contract of sale — and only when both parties sign is the deal legally locked in. Sellers who have their attorney engaged and ready to work before listing typically shrink this window meaningfully, which reduces the time during which the deal can collapse.
Do unpermitted improvements really kill Long Island home sales?
They can, and they do regularly. Unpermitted work — finished basements, decks, dormers, extensions done without a closed permit — surfaces during the title search and the buyer's attorney's due diligence. Once it surfaces, the buyer typically requests credits, a price reduction, or resolution before closing. I've seen sellers lose $30,000 to $50,000 in last-minute credits because they didn't address open or missing permits before listing. The fix is straightforward: pull your permit history, deal with open issues, and resolve missing certificates of occupancy before the listing goes live, not after a buyer's attorney forces the conversation.
What happens to my STAR exemption when I sell my Long Island home?
STAR, Enhanced STAR, Senior Citizens, and Veterans exemptions all follow the person, not the property. They do not transfer to the buyer. This means the post-sale property tax bill is often meaningfully higher than the bill you've been paying. For sellers with Enhanced STAR or other major exemptions, the gap between your current tax bill and the buyer's actual tax bill can be $5,000 to $10,000 per year or more. This affects two things: how buyers evaluate the carrying cost of your home, and how the buyer's mortgage debt-to-income ratio is calculated. Sellers should price and market their home against the true post-sale tax picture, not the exemption-reduced bill on their current statement.
Why is the $1 million mansion tax such a big deal for Long Island sellers?
Because it's a cliff, not a sliding scale. The mansion tax kicks in the moment a sale price hits $1 million, and it applies to the entire purchase price, not just the amount above the threshold. A sale at $999,999 produces zero mansion tax; a sale at $1,000,000 produces $10,000. One extra dollar of price creates a $10,000 tax bill for the buyer. For homes hovering at the $1 million line, pricing strategically just below the threshold often produces stronger outcomes — wider buyer pool, more showings, sometimes competing offers that push the final number up anyway, all without handing the buyer a $10,000 reason to walk away.
By Eric Berman, REALTOR® | The Eric Berman Team at Compass
Eric Berman | Long Island & Queens REALTOR® | Compass
1468 Northern Blvd, Manhasset, NY 11030
(917) 225-8596 | eric@ericbermanteam.com | theericbermanteam.com
