A stock purchase agreement for an S corporation is a standard share acquisition contract loaded with extra tax-focused terms because the target’s pass-through status is fragile. The entity pays no federal income tax only as long as every S corporation qualification requirement has been met without interruption since the original election. One overlooked shareholder transfer, one missing signature on the original Form 2553, one year of underpaid shareholder salaries, and the election can be treated as terminated years back, leaving the company (and its new owner) with a corporate-level tax bill the purchase price never contemplated. The agreement’s job is to allocate that risk, which is why these documents run longer and get negotiated harder than the C corporation version.
What the Agreement Has to Cover
The opening sections identify the buyer, the seller, and the exact shares being sold. That sounds mechanical, but identity matters here: if the buyer is not an eligible S corporation shareholder, closing the deal terminates the election on the spot. The agreement specifies the number or percentage of outstanding shares transferring and defines the aggregate purchase price before any post-closing adjustments.
Payment is usually cash at closing, though many deals mix in seller notes, earn-outs tied to post-closing performance, or deferred consideration. A closing mechanics section sets the date, the location, and the deliverables from each side. The seller typically hands over endorsed stock certificates and resignations from outgoing directors and officers. The buyer delivers the purchase price and any ancillary agreements such as employment or consulting arrangements.
The agreement also spells out conditions precedent: events that must occur (or not occur) before either side is obligated to close. Common ones include the absence of a material adverse change in the business between signing and closing, receipt of required third-party or regulatory consents, and continued accuracy of the seller’s representations at the closing date. If a condition is not satisfied or waived, the other side can walk away.
Representations and Warranties Specific to S Corporations
Representations and warranties are the contractual backbone of risk allocation. In a normal deal, the buyer worries about undisclosed liabilities, pending litigation, and financial statement accuracy. In an S corporation deal, the buyer carries an additional worry that dwarfs the others: the possibility that the S election was never valid, or was inadvertently terminated before closing. If either happened, the company was a C corporation all along, and every dollar of past income was subject to corporate tax that was never paid.
S Corporation Qualification
The seller has to represent that the company has continuously qualified as an S corporation since its original election. That means confirming Form 2553 was properly filed, every shareholder signed it, and the election has remained in effect for every taxable year since.
The qualification rules are strict and easy to violate. No more than 100 shareholders. Only individuals, estates, certain trusts, and certain tax-exempt organizations can hold shares. A single share transferred to a corporation, a partnership, or a nonresident alien terminates the election on the date of that transfer. Only one class of stock is permitted, meaning every outstanding share must carry identical rights to distributions and liquidation proceeds.1Office of the Law Revision Counsel. 26 U.S. Code 1361 – S Corporation Defined
The warranty has to cover every one of these requirements for the full period the election has been in place. A gap matters. If the company briefly had an ineligible shareholder eight years ago and nobody noticed, the election terminated then, and the company has been operating as a C corporation ever since. The IRS can grant relief for inadvertent terminations, but only on application, which is a process the buyer would rather not inherit.
Tax Filings and Correct Allocations
Beyond qualification, the seller warrants that the company has timely filed all required federal, state, and local tax returns, including the annual S corporation return, and that all liabilities shown are paid or reserved on the financial statements.
The seller also represents that all income and loss items were correctly allocated to shareholders on a pro rata, per-share, per-day basis for each taxable year. Incorrect allocations create exposure because the IRS can challenge the returns and assess penalties against the entity. Representations should also confirm that all shareholder consents to the original S election were properly obtained and remain valid; a missing signature on Form 2553 can invalidate the election entirely.2Internal Revenue Service. Instructions for Form 2553
Reasonable Compensation
Shareholders who work in the business are required to pay themselves a reasonable salary before taking distributions. When they don’t, the IRS can reclassify distributions as wages and assess back employment taxes at a combined rate of 15.3%, plus accuracy penalties of 20% on the underpaid amount and interest from the original due date. This is one of the most common S corporation audit triggers, and the liability rides with the entity.
The buyer should insist on representations that all shareholder-employees received compensation consistent with fair market value for their services during the pre-closing period, and that employment taxes on that compensation were properly withheld and remitted. Without this warranty, the buyer inherits the risk that the IRS reclassifies years of low-salary, high-distribution arrangements and sends the bill to the company.
Built-In Gains Tax Exposure
If the S corporation used to be a C corporation, separate representations are needed for the built-in gains tax. On conversion, the corporation faces a corporate-level tax on any net gain recognized from selling assets that were held on the date of conversion, provided the sale occurs within the five-year recognition period following the conversion. The tax runs at the highest corporate rate under Section 11(b), currently 21%.3Office of the Law Revision Counsel. 26 U.S. Code 1374 – Tax Imposed on Certain Built-In Gains
The seller should represent the exact date the S election became effective, confirm whether the corporation was previously a C corporation, and disclose the fair market value and tax basis of all assets as of the conversion date. If the five-year recognition period has not yet expired at closing, the buyer needs to know the remaining duration and the total built-in gain exposure. A seller who glosses over this could leave the buyer facing a substantial corporate-level tax bill when the company later sells appreciated real estate or equipment that was on the books before conversion.
Employee Retention Credit Claims
For any target that claimed the Employee Retention Credit for wages paid between March 2020 and December 2021, the agreement should include specific representations about the validity of those claims. The IRS has been aggressively auditing ERC claims and has identified widespread ineligibility. The credit was only available to employers that experienced a government-ordered suspension of operations or a significant decline in gross receipts during the qualifying period.4Internal Revenue Service. Frequently Asked Questions About the Employee Retention Credit
The seller should represent whether the target claimed the ERC, the total amount, and the factual basis for eligibility. If the company also received a Paycheck Protection Program loan, the representations need to confirm that the same wages were not used both for PPP forgiveness and for the ERC, since double-dipping is prohibited.4Internal Revenue Service. Frequently Asked Questions About the Employee Retention Credit The buyer should ask for supporting documentation, including PPP forgiveness applications and calculations showing no wage overlap. An improperly claimed ERC that gets clawed back becomes the company’s liability after closing unless the agreement shifts that risk to the seller.
Allocating Income for the Year of the Sale
When S corporation shares change hands mid-year, both sides need to decide how the company’s income and losses get divided between the selling and buying shareholders. The default rule allocates each item of income, loss, deduction, and credit on a pro rata basis across each day of the taxable year and assigns each day’s share to whoever owned the stock on that day. That per-day, per-share method applies automatically unless the parties affirmatively choose something different.
The alternative is a closing-of-the-books election under Section 1377(a)(2), which treats the taxable year as two short years: one ending on the sale date and one beginning the day after.5Office of the Law Revision Counsel. 26 U.S. Code 1377 – Pro Rata Share Under the election, each shareholder group is taxed only on income the company actually earned during their period of ownership. Every affected shareholder and the corporation itself must consent.
The choice matters financially. If the company earns most of its income in the first half of the year and closes in June, the per-day method pushes some of that pre-closing income onto the buyer. The closing-of-the-books method keeps it with the seller. The agreement should specify which method the parties will use and include the seller’s covenant to cooperate in making the election if the closing-of-the-books approach is chosen. Leaving this open creates a dispute almost guaranteed to surface during the first post-closing tax season.
Purchase Price Adjustments and the Stub-Period Tax Distribution
The headline purchase price is rarely the final number. The agreement includes a mechanism for post-closing adjustments that reconcile the price against the company’s actual financial condition on the closing date.
Working Capital and Net Debt
Most S corporation acquisitions use a cash-free, debt-free pricing model with a working capital adjustment. The parties agree on a target working capital level, typically based on a trailing average. If actual working capital at closing falls below the target, the purchase price is reduced dollar-for-dollar. If it exceeds the target, the buyer pays the difference. Net debt (outstanding loans and similar obligations minus cash on hand) is handled separately: debt is subtracted from the purchase price and excess cash is added, so the buyer pays only for the operating business.
These adjustments are calculated from a closing-date balance sheet that the buyer or an independent accountant prepares after closing. The agreement specifies the accounting principles used, a timeline for delivering the draft balance sheet, a dispute resolution procedure, and a deadline for the true-up payment. Sloppy definitions here generate more post-closing disputes than almost anything else in the document.
Tax Distribution for the Stub Period
Because the S corporation is a pass-through entity, the selling shareholders owe personal income tax on the company’s earnings through the closing date, even if the cash those earnings represent stays in the business. The agreement should require the company to make a pre-closing or concurrent tax distribution to cover the sellers’ tax liability on that stub-period income.
The distribution amount is calculated by multiplying the company’s net taxable income for the stub period by an assumed combined federal and state tax rate. The assumed rate is typically the highest marginal individual rate, since S corporation income is taxed at individual rates.6Internal Revenue Service. S Corporations Without this provision, the seller is stuck with a tax bill and no cash to pay it. Buyers sometimes resist the distribution because it reduces working capital, which is why the working capital target and the tax distribution calculation need to be coordinated.
Transaction Expense Allocation
Legal fees, accounting costs, investment banker fees, and other transaction expenses can be substantial. The agreement should clearly assign responsibility for these costs between the buyer, the seller, and the target company. For income tax purposes, expenses incurred to facilitate the transaction must be capitalized: the buyer capitalizes them into the basis of the purchased stock, and the seller treats them as a reduction of sale proceeds. Non-facilitative expenses such as general due diligence costs may be currently deductible, but the taxpayer bears the burden of proving the distinction. Getting this wrong affects both the buyer’s future tax basis and the seller’s recognized gain.
Escrow
A portion of the purchase price, commonly between 5% and 15%, is deposited into escrow at closing. A neutral third-party agent holds the money as the buyer’s first source of recovery if the seller breaches a representation or owes indemnification. In an S corporation deal, a separate tax escrow is often set up specifically to cover exposure from a challenge to the S election or a built-in gains tax assessment. The tax escrow is usually larger than the general indemnity escrow and has a longer hold period, reflecting the extended statute of limitations for tax matters. The agreement specifies release conditions, the dispute resolution mechanism if both sides claim the funds, and interest allocation during the holdback period.
The Section 338(h)(10) Election
One of the most powerful planning tools in an S corporation acquisition is the Section 338(h)(10) election. It lets the buyer and seller treat a stock purchase as if the target had sold all of its assets and then liquidated. The legal form is still a stock sale, so the buyer takes the target’s entity and all its contracts, permits, and legal relationships. But for tax purposes, the buyer is treated as purchasing the target’s individual assets at fair market value, creating a stepped-up basis that generates larger depreciation and amortization deductions going forward.7Internal Revenue Service. Instructions for Form 8023
The election has requirements. The buyer must be a corporation, and the acquisition must be a qualified stock purchase: at least 80% of the target’s voting power and value acquired within a 12-month period. If the target is an S corporation, every shareholder must consent, including those not selling their shares.7Internal Revenue Service. Instructions for Form 8023 The gain on the deemed asset sale flows through to the selling shareholders on the S corporation’s final return, taxed at their individual rates rather than at the corporate level. The election is made by filing Form 8023 jointly by the 15th day of the ninth month following the acquisition.
The seller’s willingness to make this election is a major negotiation point. The stepped-up basis is enormously valuable to the buyer, but the deemed asset sale may accelerate the seller’s tax liability compared to a straight stock sale. The purchase price often reflects a premium to compensate the seller for the additional tax cost, and the agreement needs covenants requiring both sides to cooperate in making and preserving the election.
Section 336(e) When the Buyer Isn’t a Corporation
When the buyer is not a corporation (an individual or a partnership, for example), the 338(h)(10) election is unavailable. Section 336(e) offers similar deemed-asset-sale treatment for qualified stock dispositions of at least 80% of a target’s stock within a 12-month period. The difference is that the election is made by the seller and the target corporation rather than jointly with the buyer. The seller and target must enter into a binding written agreement by the due date of the target’s tax return for the year of the disposition.8eCFR. 26 CFR 1.336-2 – Qualified Stock Dispositions Because the buyer has less control over whether this election is made, the agreement should include a covenant from the seller either committing to make the election or agreeing not to make it without the buyer’s consent, depending on which outcome the buyer wants.
Indemnification and Survival Periods
Indemnification is where the representations get their teeth. Without it, a breached warranty is just a broken promise. With it, the seller is contractually obligated to compensate the buyer for losses caused by the breach. The standard framework has three moving parts: the basket, the cap, and whether claims are calculated on a deductible or first-dollar basis.
The basket sets a minimum threshold of aggregate losses the buyer must accumulate before any indemnification claim can be triggered. Structured as a deductible, the seller only pays for losses exceeding the threshold. This prevents nuisance-level claims. The cap limits the seller’s maximum aggregate exposure for breaches of general representations, typically expressed as a percentage of the purchase price. Claims based on fraud or breaches of fundamental representations (ownership of shares, authority to sell, capitalization) are usually excluded from the cap entirely.
Tax Carve-Outs
Tax claims in an S corporation deal are almost always carved out from the general indemnification framework and given their own, more buyer-friendly terms. The reason is simple: if the S election turns out to have been invalid, the resulting corporate-level tax liability could exceed the purchase price. A general cap at 10% or 15% of deal value would be meaningless in that scenario.
For that reason, the tax indemnity cap is typically set much higher than the general cap. In many deals, the seller’s exposure for pre-closing tax liabilities is uncapped or capped at 100% of the purchase price. Tax claims are also carved out of the basket, giving the buyer first-dollar recovery. The buyer should not have to absorb any portion of a tax liability caused by the seller’s failure to maintain the S election or properly report income during the pre-closing period.
Survival Periods
Every representation expires after a defined survival period. Once it expires, the buyer loses the right to bring an indemnification claim based on it. General representations typically survive for 12 to 24 months after closing, enough time for the buyer to work through a full annual cycle and surface operational or financial problems.
Tax representations survive much longer. The standard approach ties survival to the applicable statute of limitations for tax assessments, plus a buffer for administrative or judicial appeals. The general federal assessment period is three years from the date the relevant return was filed.9Internal Revenue Service. Overview of Statute of Limitations on the Assessment of Tax That period extends to six years if the taxpayer omits from gross income an amount exceeding 25% of the income reported on the return.10Office of the Law Revision Counsel. 26 U.S. Code 6501 – Limitations on Assessment and Collection In cases of fraud, there is no limitation period at all. The agreement should set the tax representation survival period at the longest potentially applicable limitations period plus 60 to 90 days, so the buyer can still bring a claim even if the IRS acts near the deadline.
Keeping the S Election Alive After Closing
Everything above focuses on what happened before closing. But the S election can just as easily die the moment the deal closes if the buyer is not an eligible shareholder. The agreement should include covenants from the buyer confirming that acquiring the shares will not cause the corporation to cease qualifying as a small business corporation. If the buyer is a C corporation, the S election terminates immediately on transfer.11Office of the Law Revision Counsel. 26 U.S. Code 1362 – Election; Revocation; Termination Courts have upheld termination even when only a single share ended up in ineligible hands.
Buyers planning to maintain S status should also know that several states do not recognize the federal S corporation election and impose entity-level taxes on S corporations as though they were C corporations. Federal pass-through treatment is not a guarantee of pass-through treatment at the state level. Due diligence should include a state-by-state look at where the target operates, files returns, or has nexus.
When the buyer is an entity that would terminate the election (a corporation, or a private equity fund structured as a partnership, for instance), the parties often pair the stock purchase with a Section 338(h)(10) election so the deemed asset sale locks in pass-through treatment on the final S corporation return. Alternatively, the buyer may form a new S corporation or use an eligible holding structure to acquire the shares while preserving the election. The agreement needs to state whether the parties intend to preserve the election, terminate it, or make a deemed-asset-sale election, and it should carry the covenants and cooperation obligations that match that intent.