Pre-Sale Tax Planning: The Decisions That Have to Happen Before You Sign

Why timing matters more than most founders realize

For adjacent context, compare this with Earnouts in M&A: Why Founders Don't Get Paid What They Expect; the strongest operators connect these topics instead of treating them as separate workstreams.

Tax planning for a business sale is not something that happens at the closing table. The decisions with the largest dollar impact, entity structure, stock qualification, pre-sale reorganization, charitable planning, must be made months or years in advance. By the time a <a href="/insights/letter-of-intent-ma-founder-guide" class="subtle-link">letter of intent</a> is signed, most of the tax outcome is already determined by choices that were made, or not made, long before. The asset sale vs. stock sale comparison covers the structural choice that most directly affects the tax outcome.

Many founders assume the accountant will handle tax structure, after 15 years building a business, the focus is naturally on deal price. Engaging a transaction tax advisor only after the LOI is signed is a common outcome. By then, the most valuable planning windows have closed. The difference between a founder who planned 3 years ahead and one who waited until the LOI can easily exceed $2M in after-tax proceeds on a $20M transaction.

The typical founder who has not engaged a tax advisor before engaging an investment banker is not choosing between strategies. They are accepting whatever outcome their current structure produces. In the lower middle market, that can easily mean a $1–3M difference in after-tax proceeds on a $15–20M transaction.

Entity structure: the decision most founders cannot change in time

The biggest structural tax decision is whether your business is a C-corp or a pass-through (S-corp, partnership, LLC). In an asset sale, the most common structure in lower-middle-market deals, C-corp shareholders face double taxation: corporate-level tax on the asset gains, then dividend tax when proceeds are distributed. Pass-through entities pay only once at the shareholder level.

Converting a C-corp to an S-corp before a sale can reduce this burden, but the IRS imposes a 5-year built-in gains (BIG) period. Assets that appreciated before the S-corp election are still subject to corporate-level tax if sold within 5 years. The conversion only fully benefits founders who plan 5 or more years ahead.

Converting from S-Corp to C-Corp before a sale: when it makes sense

The entity structure discussion almost always focuses on the double-taxation problem facing C-corps in asset sales. Less discussed is the reverse scenario: an S-corp or LLC founder who should consider converting to a C-corp before a sale to unlock QSBS eligibility or to enable a Section 368 tax-free reorganization. Both benefits require C-corp status, and both require time to become available.

The primary reason to convert from S-corp to C-corp is Section 1202 QSBS eligibility. QSBS requires C-corp stock, S-corp shareholders and LLC members do not qualify. A founder who has operated as an S-corp for 12 years and wants the $10M federal exclusion must convert to C-corp status and then hold the newly issued C-corp stock for at least 5 years before a qualifying sale. The holding period clock starts at conversion, not at formation. A second reason is Section 368: tax-free stock-for-stock reorganizations require both the acquirer and target to be corporations, and S-corps generally cannot participate without converting first.

The built-in gains tax is the primary economic obstacle. Under Section 1374, when an S-corp converts to C-corp status, the IRS tracks the "built-in gain", the appreciation in assets that existed at the conversion date. If the company sells within 5 years of conversion, gains attributable to pre-conversion appreciation are subject to a 21% corporate-level tax, in addition to any shareholder-level tax on the distributed proceeds. For founders expecting a sale within 5 years of converting, the BIG tax can eliminate most of the economic benefit of converting.

The conversion makes mathematical sense when: (1) the founder plans to hold the business for at least 5 years post-conversion, clearing both the BIG recognition period and the QSBS holding requirement; (2) the expected gain at exit is large enough that the $10M QSBS exclusion (~$2.38M of federal tax savings) exceeds the combined cost of the conversion and any residual BIG tax; or (3) a public company acquirer is offering stock consideration and the founder needs C-corp status to access Section 368 tax-free reorganization treatment. When the timeline is shorter than 5 years, or when the built-in gain is large relative to the anticipated QSBS benefit, the conversion often does not make economic sense and the founder is better served by optimizing within the existing S-corp or pass-through structure.

Section 1202 QSBS: the exclusion most founders overlook

Section 1202 of the tax code allows shareholders of qualified small business stock (QSBS) to exclude up to $10M in capital gains (or 10x their adjusted basis, whichever is greater) from federal tax. For founders who qualify, this is one of the most valuable provisions in the tax code, and one of the least understood.

Qualification requirements are specific: the company must be a C-corp (not S-corp, not LLC) when the stock is issued, must have less than $50M in gross assets at the time of issuance, must be engaged in a qualified trade or business (most manufacturing, technology, and service businesses qualify; professional services like law and consulting do not), and the founder must have held the stock for at least 5 years.

The catch is that QSBS only applies to C-corp stock. S-corp shareholders and LLC members do not qualify. Founders who converted from C-corp to S-corp for pass-through treatment have likely forfeited QSBS eligibility on shares issued after conversion, and may have a decision to make about whether to convert back, depending on how much appreciation remains and the timeline to exit.

Installment sales, charitable structures, and other pre-close tools

For founders who cannot use QSBS (wrong entity type, too late to qualify, assets exceed the threshold), installment sales and charitable structures are the primary remaining tools.

An installment sale allows a seller to spread gain recognition across years, paying tax only as principal is received rather than all at once at closing. This is useful when a founder expects to be in a lower tax bracket in future years, or when spreading income avoids triggering additional surtaxes. The mechanics are straightforward for all-cash deals structured with a seller note; they are more complex with earnouts.

A charitable remainder trust (CRT) allows a seller to contribute pre-close stock to a trust, which then sells the stock tax-free, reinvests the proceeds, and pays the founder an income stream for life or a term of years. At the end of the trust term, the remaining assets pass to charity. The founder avoids immediate capital gains on the full sale, receives a partial charitable deduction at contribution, and draws income from the trust. This is not a tool for every transaction, it requires meaningful charitable intent and gives up control of the principal, but for founders with philanthropic goals and large expected gains, the math can be compelling.

A grantor retained annuity trust (GRAT) is a different tool with a different purpose: it is an estate-freeze technique that transfers business appreciation to heirs with reduced gift and estate tax exposure, not a method for reducing income tax on the sale itself. The founder transfers business interests, typically a minority LLC interest or shares in the company, into the GRAT, which pays the founder a fixed annuity for a defined term (commonly 2–5 years).

If the business appreciates at a rate above the IRS hurdle rate (the Section 7520 rate, published monthly), that excess appreciation passes to the trust beneficiaries, typically the founder's children, gift-tax-free. A "zeroed-out" GRAT is structured so the present value of the annuity equals the value of the contributed assets: if the business grows faster than the 7520 rate, heirs receive the excess at zero gift tax cost. When a business sale occurs during the GRAT term, the sale proceeds flow into the trust and continue funding the annuity.

GRATs work best when set up 2–3 years before a transaction, if a sale is imminent, both the 7520 rate and the valuation discount on the contributed interest must be favorable for the transfer to generate a meaningful benefit. Founders who expect a business sale within 5 years should ask their estate planning counsel specifically whether a GRAT makes sense given current 7520 rates.

338(h)(10) election mechanics: how buyers use it and how to price it

A 338(h)(10) election is a joint election made by buyer and seller that treats a stock sale as an asset sale for federal tax purposes. It is available only when the target is an S-corporation (or a subsidiary of a consolidated group). When elected, the buyer receives a step-up in the tax basis of the underlying assets to fair market value, which allows them to generate additional depreciation and amortization deductions post-close. The seller, however, is taxed as if they sold the assets, not the stock, which means a higher effective tax rate on the gain.

Why do buyers request 338(h)(10) elections? Asset basis step-up is economically valuable. On a $30M purchase price for an S-corp with a fully depreciated asset base, the step-up generates meaningful future deductions. PE buyers and strategic acquirers both model this benefit. In a low-interest-rate environment, the NPV of the tax shield can approach 8–12% of the asset value being stepped up.

The gross-up negotiation works as follows: the seller calculates the incremental federal (and often state) tax cost of accepting asset treatment versus stock treatment. The buyer offers a price premium equal to that differential, sometimes partially, sometimes fully. In practice, the gross-up range is 5–10% of purchase price, and it is negotiated like any other deal term, buyers start low, sellers start high. Sellers who have not modeled this before the LOI stage consistently accept below-market gross-ups because they do not have the calculation ready. The gross-up should be modeled as part of every LOI review for any S-corp transaction.

Opportunity Zone reinvestment: the 180-day window founders miss

Qualified Opportunity Zone (OZ) reinvestment is a tax deferral and exclusion mechanism available to sellers who reinvest capital gains into a qualified opportunity fund within 180 days of the sale. For founders with large capital gains and a tolerance for illiquid investment exposure, it is one of the most powerful post-close tax planning tools available.

The mechanics are straightforward: within 180 days of realizing a capital gain, the seller reinvests the gain amount into a Qualified Opportunity Fund (QOF). The gain is deferred until December 31, 2026 or until the investment is sold, whichever comes first. The basis in the QOF investment starts at zero, meaning any gain on the investment itself is subject to tax, but there is a critical exclusion for long-term holders.

The most important benefit is the 10-year permanent exclusion. A seller who reinvests $5M of capital gains into a QOF, holds the investment for 10 years, and realizes $8M in appreciation pays zero federal capital gains tax on the $8M of appreciation, only the original $5M deferred gain (recognized no later than December 31, 2026) is subject to tax. The OZ program does not eliminate the original gain; it defers and partially reduces it, and eliminates all appreciation above the original investment.

State conformity varies significantly. Some states (California, for example) do not conform to the federal OZ provisions, meaning the state-level gain is not deferred even when the federal gain is. Founders in high-state-tax jurisdictions should model the state tax separately when evaluating OZ as a planning tool.

Installment sales and earnouts: the tax interaction most founders get wrong

An installment sale allows a seller to recognize gain over multiple years as principal payments are received, rather than recognizing the full gain at the time of closing. This defers tax and can reduce effective rates if the seller expects to be in a lower bracket in future years. The mechanics are well-established for straightforward structures, a seller note or deferred payment at a fixed amount.

Earnouts create meaningful complexity in the installment sale framework. When a deal includes an <a href="/insights/earnouts-ma-why-founders-dont-get-paid" class="subtle-link">earnout</a>, the total purchase price is not fixed at closing, so the gain calculation cannot be completed at that moment. The IRS addresses this through the open transaction doctrine and the contingent payment rules, which determine how gain is recognized in each year as earnout payments are received. The tax treatment depends on whether the earnout is contingent on the performance of the business (normal) or is structured as a retained interest in the business (which could be treated differently).

The installment method is unavailable when the consideration received includes publicly traded stock (or other publicly traded property). If a strategic buyer pays part of the purchase price in their own publicly traded stock, the full fair market value of that stock is recognized as income in the year of sale, the installment benefit is gone for that portion. This is a material consideration in deals where stock consideration is part of the offer structure, and it argues for ensuring the consideration structure is analyzed by a transaction tax advisor before the LOI is signed.

One additional trap: if a seller elects installment treatment and then sells the installment note to a third party (such as pledging it as collateral), the deferred gain can be triggered immediately. Founders who take a seller note as part of deal proceeds and then attempt to monetize that note face this acceleration risk.

State tax residency planning before a sale

State income tax on a business sale can be the largest avoidable cost in the transaction for founders in high-tax states. California taxes capital gains at ordinary income rates (13.3% top rate). New York adds 10.9% state plus New York City rates. A founder selling a $20M equity stake could owe $2.6M–$3.0M in state taxes that a Florida or Texas resident would not pay.

Residency-based state tax planning is legal and, when properly executed well in advance of a sale, effective. The key is that the change of residency must be genuine: domicile (primary legal home) must move, and the founder must sever ties with the high-tax state sufficiently to survive an audit. States like California are aggressive about residency challenges and will audit founders who claimed to move shortly before a large transaction.