Stock Purchase vs. Asset Purchase: The Deal Structure Decision Every Founder Must Get Right Before Selling

When a founder receives a letter of intent to acquire their startup, the first question is usually "How much?" The second should be "How?" — as in, how is the deal structured? The choice between a stock purchase and an asset purchase determines whether the company's liabilities travel with the business to the buyer or stay behind with the selling entity, which contracts survive the transaction, how the tax bill splits between the corporation and its shareholders, and whether founders walk away clean or carry residual exposure for years. It is, in our experience, the single most consequential structural decision in an M&A transaction — and too many founders defer to the buyer's preference without understanding the trade-offs.

What Stock Purchase and Asset Purchase Actually Mean

In a stock purchase, the buyer acquires the founders' shares directly. The corporate entity — your Delaware C-corp, your Texas LLC, whatever holding company you built — continues to own its assets, contracts, licenses, and liabilities exactly as before. The only thing that changes is who owns the equity. The buyer steps into the shoes of the selling shareholders and, by extension, inherits the entire corporate package: assets, obligations, pending litigation, tax positions, and all.

In an asset purchase, the buyer selects specific assets — intellectual property, equipment, customer lists, lease rights — and purchases them directly from the entity. The selling entity retains its legal identity, along with whatever liabilities the buyer declined to assume. The founders' shares remain outstanding, but the company underneath them has been hollowed out: it holds cash from the sale and whatever liabilities were not transferred.

The distinction sounds technical, but the downstream consequences are enormous. A stock purchase is buying the company; an asset purchase is buying the company's stuff. That difference shapes every negotiation that follows.

The Liability Question: Who Inherits What

This is where the structural choice matters most to founders.

In a stock purchase, the buyer inherits all of the target's liabilities — known, unknown, contingent, and yet-to-be-discovered. If the company faces a product liability claim six months after closing, that claim belongs to the buyer. If the IRS audits a prior-year return and assesses additional tax, the buyer's entity pays it. Founders, having sold their shares, are generally out of the liability chain — though buyer-side indemnification provisions (typically secured by escrow or holdback of a portion of the purchase price) can claw back exposure for a negotiated survival period, usually 12 to 24 months.

In an asset purchase, the buyer assumes only the liabilities expressly identified in the asset purchase agreement. Everything else — pending lawsuits, unpaid vendor invoices, tax obligations, employment claims, environmental liabilities — remains with the selling entity. The buyer gets a clean slate. The founders, by contrast, are left holding a shell company that still owes those obligations. If the sale proceeds are insufficient to cover the retained liabilities, founders may face personal exposure depending on the entity structure and any personal guarantees they signed.

This is why buyers overwhelmingly prefer asset purchases for acquisitions of smaller or early-stage companies. It allows them to cherry-pick the valuable assets while leaving behind the risk. Founders should understand that accepting an asset purchase structure without negotiating for the buyer to assume key liabilities — or without a plan to wind down the remaining entity — can leave them in a worse position than they realize.

Contract Assignment and Consent Killers

One of the most overlooked risks in M&A structures involves assignment and change-of-control clauses embedded in the target's contracts. This issue can derail an otherwise healthy deal.

Most commercial contracts — customer agreements, vendor relationships, software licenses, office leases — contain provisions restricting assignment without the other party's consent. In a stock purchase, these clauses generally do not trigger, because the contract itself isn't being assigned; the entity that holds the contract remains the same, and only its ownership changes. The contracts continue in force without interruption.

In an asset purchase, however, the contracts are being transferred from the selling entity to the buyer (or a buyer affiliate). That transfer constitutes an assignment under most contract language, which means the counterparty's consent is required. If a key customer has a change-of-control or anti-assignment clause, the buyer must obtain that customer's written consent before the contract transfers. If consent is denied — or if the customer uses the opportunity to renegotiate terms — the deal's value can erode significantly.

Delaware courts have grappled extensively with the distinction between assignment and transfer in the M&A context. In Daniel v. Hawkins, 311 A.3d 890 (Del. 2023), the Delaware Supreme Court affirmed that an assignment is a narrower term than transfer and is a type of transfer, and that contractual restrictions on assignment must be interpreted based on the specific language used in each agreement. The court's analysis underscores a critical practical point: founders cannot assume that a generic no-assignment-without-consent clause will or will not be triggered by a particular deal structure. Each material contract requires individual review.

For startups with enterprise customer agreements, government contracts, or exclusive vendor relationships, this issue alone can drive the decision toward a stock purchase structure — even if the buyer would otherwise prefer an asset deal. We recommend that founders conduct a contract-consent audit before signing an LOI. Identify every agreement that contains assignment restrictions, estimate the likelihood and timeline for obtaining consents, and factor that into the structure negotiation. If you wait until due diligence to discover that your largest customer contract cannot be assigned without consent, you have already lost leverage.

The Tax Split: Single-Level vs. Double Taxation

Tax treatment is where the stock-vs-asset choice creates the most friction between buyers and sellers, because their interests are directly opposed.

In a stock purchase, the selling shareholders recognize capital gain equal to the difference between the purchase price and their basis in the shares. For qualified small business stock (QSBS) under Section 1202, a significant portion of that gain may be excluded from federal tax entirely — up to $10 million or 10x basis, whichever is greater, for shares acquired after September 27, 2010. The entity itself recognizes no gain. This is single-level taxation, and it is generally the most tax-efficient outcome for founders.

In an asset purchase by a C-corporation, the tax story is very different. The selling corporation recognizes gain on the sale of its assets — potentially at both capital gains and ordinary income rates, depending on the nature of the assets (depreciation recapture on equipment, ordinary income on inventory, capital gain on goodwill). Then, when the corporation distributes the after-tax proceeds to its shareholders as a liquidating distribution, the shareholders recognize a second layer of tax on their gain. This is the classic double taxation problem that makes asset sales unattractive to C-corp sellers.

For S-corporations and LLCs taxed as partnerships, the double-tax problem largely disappears, because these pass-through entities do not pay entity-level tax (with limited exceptions for built-in gains tax on certain S-corps). In those cases, an asset sale generates a single level of tax at the owner level, making the tax disparity between stock and asset structures less pronounced. This is one reason why many venture-backed startups — almost universally C-corps — face a sharper structural tension than bootstrapped LLCs.

Buyers prefer asset purchases for tax reasons of their own: an asset purchase gives the buyer a stepped-up basis in the acquired assets to fair market value, which generates future depreciation and amortization deductions. In a stock purchase, the buyer takes the seller's carryover basis — typically much lower — and gets no comparable tax benefit. This step-up can be worth millions to the buyer over time, particularly when a significant portion of the purchase price is allocable to goodwill and intangibles amortizable over 15 years under Section 197.

Negotiation Leverage: When Founders Should Push Back

Understanding these dynamics gives founders a framework for evaluating — and sometimes resisting — the buyer's proposed structure.

Buyers will almost always push for an asset purchase structure, especially for early-stage or smaller acquisitions. It limits their liability exposure, provides tax benefits through basis step-up, and gives them negotiating leverage over which specific assets and contracts they take. From the buyer's perspective, an asset deal is the safer, more flexible choice.

But founders are not without leverage. If the target's contracts contain assignment restrictions that would make an asset deal slow, expensive, or risky for the buyer, that is a strong argument for a stock purchase. If the company is a C-corp and the double-tax hit would significantly reduce the founders' net proceeds, founders can negotiate for a higher purchase price to compensate — or push for a stock structure that avoids the problem entirely. If the company has clean books, strong compliance history, and well-documented contracts, the buyer's liability concerns are mitigated, making a stock purchase more palatable.

The key is to have this conversation before the LOI is signed. Once a letter of intent specifies a structure, changing it later is difficult and can signal weakness in negotiations. We have seen founders accept asset purchase terms in an LOI to keep a deal moving, only to discover later that the tax cost and liability retention made the effective purchase price far lower than the headline number suggested. For more on how early corporate decisions affect downstream outcomes, see our earlier piece on why stock issuance decisions can make or break your startup.

The 338(h)(10) Hybrid: Getting the Best of Both Worlds

There is a middle path — but it comes with strings attached. Section 338(h)(10) of the Internal Revenue Code allows the parties to a stock purchase to elect to treat the transaction, for tax purposes only, as if it were an asset purchase. The legal structure remains a stock purchase — contracts transfer automatically, no assignment consents are needed, liabilities transfer to the buyer — but the tax treatment shifts to give the buyer the stepped-up basis it would receive in an asset deal.

Under 26 U.S.C. Section 338(h)(10), this election is available only when the target is an S-corporation, a subsidiary within a consolidated group, or a selling affiliate as defined in Treasury Regulation 1.338(h)(10)-1. It must be made jointly by the buyer and all selling shareholders, and it must be filed on IRS Form 8023 no later than the 15th day of the ninth month after the acquisition date. The election is irrevocable once made.

For S-corporation sellers, the 338(h)(10) election can be a powerful tool. Because S-corps are pass-through entities, the deemed asset sale generates gain at the shareholder level — single taxation — while still giving the buyer the stepped-up basis it wants. The buyer gets the tax benefit; the seller avoids the double-tax problem that would plague a C-corp in the same scenario. The parties can negotiate a price gross-up to share the tax savings, creating a win-win structure.

For C-corporations, the 338(h)(10) election is not available. A C-corp seller facing an asset purchase — or a 338(g) election, which is the non-joint version available to buyers — will bear the double-tax cost. Founders of C-corps should understand that this structural limitation is baked into the tax code and cannot be negotiated away. The only solutions are to negotiate a higher price, convert to an S-corp (which requires a five-year built-in gains holding period before the conversion eliminates entity-level tax on pre-conversion appreciation), or push for a stock purchase without the 338 election.

It is also worth noting that state tax treatment may not conform to federal rules. Texas, for instance, has a franchise tax based on margins rather than a traditional corporate income tax, which affects how the deemed asset sale is calculated at the state level. Founders should work with tax counsel to model the after-tax proceeds under each structure before committing.

For related guidance on building a company that is ready for a clean exit — including the employment and compliance infrastructure that buyers will scrutinize — see our article on why startup employment policies cannot wait until you hire HR.

Actionable Next Steps

1. Audit your contracts before you receive an LOI. Identify every agreement with assignment or change-of-control restrictions. Knowing which contracts can and cannot transfer in an asset deal gives you leverage before the buyer raises it.

2. Model the after-tax proceeds for both structures. Work with tax counsel to calculate your net proceeds under a stock purchase, an asset purchase, and (if eligible) a 338(h)(10) election. The headline price can differ from the after-tax result by 15 to 30 percent or more.

3. Clean up your corporate records. Buyers will scrutinize your cap table, board minutes, stock issuances, and compliance history. Discrepancies create leverage for price reductions or indemnity demands. If your records are incomplete, fix them now.

4. Negotiate structure in the LOI, not after. If you want a stock purchase, push for it before the LOI is signed. Changing structure mid-deal is costly and signals weakness. If the buyer insists on an asset deal, negotiate for assumption of key liabilities and a wind-down plan for the remaining entity.

5. Understand your indemnity exposure. In a stock purchase, buyer-side indemnities are typically secured by an escrow or holdback. Know the survival period, the cap, and the baskets before you agree. In an asset purchase, your remaining entity retains the liabilities — make sure the sale proceeds are sufficient to cover them.

6. Get counsel involved early. M&A structure decisions are not reversible after closing. The cost of experienced deal counsel is a fraction of the value at stake — and far less than the cost of discovering, post-closing, that you owe taxes you did not plan for or liabilities you thought you had left behind.