Advance sell-side tax due diligence should be standard in serious M&A transaction advisory

Sellers leave meaningful value on the table in M&A transactions by failing to conduct tax due diligence in advance. A seller may not begin thinking about tax due diligence until a buyer begins its due diligence, typically after a letter of intent is signed. The process then proceeds on the buyer’s timeline. This M&A norm is a structural weakness for the seller. It prevents sellers from discovering and fixing issues in advance and presenting a better narrative in negotiations. Once the two parties are already engaged, it’s much harder to address issues efficiently.

Sell-side due diligence should occur months before going to market, with a focus on remediating existing tax issues and evaluating the strongest transaction structure. Sellers can then address their needs on their own terms, rather than in reaction to buyer scrutiny and under time pressure.

Remediating existing tax issues

Buy-side and sell-side due diligence processes have distinctly different focuses. The buyer hones in on risk identification and mitigation: quantifying exposures and translating them into indemnities, escrows, purchase price reductions or special deal terms. The seller should also identify risks, but for the purpose of actively remediating them. When issues are discovered, the seller should take corrective action before involving buyers. This can include:

• Filing amended or delinquent tax returns
• Pursuing voluntary disclosures to reduce penalties and lookback periods
• Implementing accounting method changes or elections
• Cleaning up entity classification or nexus issues
• Collecting sales tax exemption certificates

Buyers should then come into the picture when their diligence process won’t uncover severe problems, because those were already resolved. Handling issues without buyer scrutiny is particularly valuable given the pressures of competitive or auction-style processes, and because buyers often emphasize worst-case scenarios. This improves the seller’s negotiating leverage and deal certainty.

Produce a credible sell-side tax report, supported by orderly data and clear explanations, as part of your marketing materials. This confidence-booster can narrow the focus of a buyer’s diligence, saving time and money.

Ideal transaction structure

In addition to identifying and fixing tax issues, sellers should evaluate transaction structure to optimize after-tax proceeds. Structuring decisions, particularly stock versus asset sales, can materially impact seller economics. For example, selling S corporation stock versus S corporation assets can produce very different outcomes depending on basis, built-in gains, and other tax attributes.

Modeling these scenarios in advance helps sellers respond effectively if a buyer expresses a structure preference. If the buyer wants to structure the deal in a way that causes the seller to pay more taxes, then both sides should clearly understand how much the seller stands to lose. That understanding can justify increasing the price (“grossing it up”) so the seller isn’t worse off.

This analysis typically includes:

• Evaluation of shareholder outside stock basis
• Preparation of a tax basis balance sheet, including identification of potential depreciation or amortization recapture
• Assessment of entity-level tax attributes, such as net operating losses or credit carryforwards, which may offset taxable gain

A comprehensive view of the seller’s tax profile supports informed decision‑making. This allows sellers to assess tax tradeoffs across deal structures before terms are dictated by the buyer – helping preserve value and improve execution certainty.

The bottom line

Sell-side due diligence is no longer a defensive exercise. It’s a strategic tool to influence price, terms, control, and sale certainty. Sellers that delay it until the exclusivity phase are negotiating with less information and ceding control. Advance diligence means breathing room, confidence, and more realized value. With extensive experience on both sides of the deal, we’re able to identify and prioritize the issues that will likely materially impact your sale.

As M&A processes become increasingly competitive and scrutinized, being well-prepared should be standard practice. Sellers who take this approach benefit from experienced guidance in navigating the tax complexities and structuring decisions that drive results. At the same time, tax law often changes at the federal and state levels. We stay ahead of these changes – so your deal strategy does too.