You just deposited the biggest check of your life. The relief is real. And then a few months later, a tax bill arrives that is bigger than any single number you have ever written to anyone — and it turns out the size of that bill wasn't determined by when you sold. It was determined by how the deal was structured.
Stock sale or asset sale. How the purchase price got allocated across categories. Whether there's an earnout, and how the payments get recognized. Which state you lived in on closing day. Those details, buried in a document you probably skimmed, are what actually decide whether you hand thirty cents of every dollar to the government or closer to fifty. Tax planning for a business sale isn't a post-closing activity. It's a pre-closing one, and most of the biggest levers are already locked in by the time the wire hits.
Why Structure Decides Everything
In an asset sale, the IRS makes you break the purchase price into categories under Section 1060 — equipment, inventory, customer lists, goodwill — and each category gets taxed differently. Goodwill typically makes up forty to sixty percent of the price, and it gets the worst treatment of the bunch: ordinary income rather than capital gains. That means 37% federal, plus state, plus the 3.8% net investment income tax. On a goodwill dollar, you can end up paying close to forty-five cents.
A stock sale flips that math. The proceeds are taxed at long-term capital gains rates, which can be roughly half. On a $5M deal, the gap between those two structures alone can reach seven figures. Stock sales aren't always on the table — buyers often prefer asset deals because they get to step up basis and avoid inheriting your liabilities — but when a stock sale is available, the tax difference is usually the single biggest dollar lever in the transaction. Depreciation recapture is the companion surprise. Every depreciation deduction you claimed over the years gets recaptured at sale — equipment and vehicles at ordinary rates, real estate at 25%, plus state. Sellers who assumed everything was capital gains often find a large slice of proceeds taxed much higher.
Levers That Only Work If You Plan Early
A few of the biggest wins have to be set up months or years before closing. Installment sales let you spread gain recognition across the years payments actually arrive — useful if part of the price is paid through an earnout or seller financing, because you can drop into lower brackets in quieter years and build in time for offsetting moves. The catch is buyer default; the tax treatment changes if payments stop, so the election needs to be modeled before the structure is signed.
State planning is another big one. California, New York, and Illinois layer 13 to 14% on top of federal capital gains. Nine states — Texas, Florida, Tennessee, Wyoming, and others — charge nothing at all. On a large deal, where you're domiciled on closing day is a real financial decision, not just a lifestyle one. C-corp to S-corp conversions need at least five years of runway to avoid the built-in gains trap that crushes C-corp exits. Qualified opportunity zones can defer and partially exclude gain if proceeds are reinvested in designated areas. Charitable remainder trusts can convert highly appreciated assets into lifetime income plus a deduction. And simply timing the close to a lower-income year can shift brackets in your favor.
None of these exist on closing day. They're planning decisions, which is why the best window to reduce your tax bill is the eighteen to twenty-four months before you list.
The Earnout Tax Trap
Earnouts look like upside — if the business performs, you get paid more. In practice, the tax side is where many sellers get hurt. The IRS recognizes each earnout payment as gain in the year received, which can push you into a higher bracket in an otherwise quiet year. If you've moved states, you may owe tax to your old state on income accrued while you were already gone. And buyers have every incentive to structure earnout metrics they can quietly miss — which doesn't retroactively refund the tax you already accrued or paid.
Sarah sold her marketing agency for $5M up front, plus a $1M earnout if year-two revenue hit target. She planned her taxes against $6M of gain. In year two, revenue hit the number — but the buyer had changed their accounting method, and under the new method revenue came in lower and the earnout wasn't, in their view, triggered. Sarah had already paid tax on the accrued gain. She's now in a dispute trying to recover money she already sent to the IRS, and the whole thing traces back to one vague word in the purchase agreement — "revenue" — that was never precisely defined. Specificity in the deal documents would have cost a few thousand dollars. The dispute is costing her hundreds of thousands.
Common Mistakes and a Workable Timeline
The patterns show up again and again. Waiting until after closing to talk to a tax advisor, when the decisions that mattered most are already locked in. Accepting the buyer's Section 1060 allocation without pushback, even though that allocation is almost always written to favor their tax position, not yours. Treating earnout payments like regular cash. Moving states mid-deal without understanding nexus rules. Forgetting extensions and estimated payments — the penalties on a large gain compound fast.
A workable timeline is simpler than it sounds. Now, before anything else, get a tax professional engaged and review the deal structure through a tax lens. At close, make sure the allocation is documented and every election you qualify for is filed. Within thirty days, understand your state liability and get estimated payments in. Ongoing, especially with an earnout, track every payment and coordinate annually. Simpler sales — single state, clean structure, mostly cash at close — can be handled with online tax tools and a tax-aware accountant. Larger or more complex deals, with earnouts, multi-state exposure, or C-corp structures, usually justify a specialist who lives in business-sale tax work.
The numbers above are directional, and every situation is different. Before you make structural decisions that will shape your after-tax proceeds for decades, work through the specifics with your own tax professional — ideally one who has advised business sellers through closings before.
Torch helps owners plan before, during, and after a sale — so the tax strategy, the deal structure, and the net proceeds actually line up with the life you're trying to fund on the other side of closing.