INSIGHT

Why Deals Fall Apart in Due Diligence and How Sellers Can Prevent It

Craig Hamm • July 15, 2026

Services: Due Diligence Services

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You’ve found a buyer, negotiated a price, and signed a letter of intent. The hard part is over, or so it seems. Due diligence is where many deals quietly unravel, and the seller’s side of the table often bears more responsibility for that outcome than people realize. Messy financials, incomplete records, and surprises that could have been addressed months earlier – these are the things that spook buyers, invite price reductions, and sometimes kill transactions entirely.

4 Common Reasons Deals Fall Apart in Due Diligence and How to Avoid Them

This article walks through the most common reasons deals fall apart in due diligence and what sellers can do before they ever get to market to protect both the deal and the price.

1. Financial Records That Don’t Hold Up

Buyers hire advisors to conduct a quality of earnings analysis, and that process digs into the details behind reported revenue, margin, and EBITDA. When the numbers don’t reconcile cleanly, when GAAP hasn’t been followed consistently, or when the financials depend on owner adjustments that are hard to document and defend, the buyer’s confidence drops, and so does the offer.

Problems that come up regularly include revenue recognized too early, expenses run through the business that reflect personal use, and working capital balances that don’t reflect how the business operates. None of these are necessarily deal-breakers on their own. But when a buyer’s advisors start finding issues, they start looking harder. One problem becomes three, and three becomes a conversation about repricing or walking away.

Sellers who invest in sell-side due diligence before going to market understand what their buyers will find and can address issues before they become leverage in a negotiation.

2. Tax Liabilities That Surface at the Wrong Time

Tax due diligence covers a wide range: federal, state, and local income taxes, sales tax, payroll tax, and transfer taxes that may apply to the transaction itself. Sellers who haven’t stayed current on state tax nexus obligations, who haven’t filed correctly in states where they’ve created a tax presence, or who have open years with unresolved issues create risk that buyers will price into the deal, or ask to be indemnified against.

This comes up often in businesses that have grown quickly and expanded into new states without updating their tax compliance posture. A sale event brings everything into focus, and tax issues that were easy to ignore during normal operations become urgent when a buyer’s tax advisors are reviewing three years of returns.

3. Contracts, Customer Concentration, & Missing Documentation

Buyers want to know what they’re acquiring and whether it will hold together after the transaction closes. That means reviewing customer contracts, vendor agreements, key employee arrangements, and intellectual property ownership. If your largest customers account for an outsized share of revenue, buyers will ask hard questions. If contracts are verbal, expired, or contain change-of-control provisions that give counterparties an exit, that’s a structural problem.

Document gaps also slow everything down. When sellers can’t produce contracts quickly, or when key agreements were never formalized, the data room turns into a back-and-forth that burns time and trust. Buyers start wondering what else isn’t in order.

Getting documentation organized before the process starts – and knowing which contracts carry change-of-control language – gives sellers time to address problems proactively rather than defensively.

4. Operational Surprises Buyers Didn’t Expect

Financial and legal issues get the most attention, but operational findings carry real weight too. Buyers evaluate management depth, customer relationships, systems and processes, and whether the business can function after the founder or key owner exits. If the business runs through one person, that’s a concentration risk. If your systems are outdated and manual, integration costs go up. If key employees haven’t been offered any transition incentives, buyers worry about what walks out the door at close.

Operational readiness isn’t something you can manufacture in a few weeks. Sellers who build management depth, document key processes, and think about retention well before a sale are in a better position than those who start that work after they’ve signed an LOI.

The Case for Sell-Side Preparation

Sellers who prepare before going to market are protecting their valuation. Price adjustments in M&A transactions often trace back directly to findings in due diligence.

Cleaning up your financial records, getting ahead of tax issues, organizing documentation, and understanding your business’s risk profile in advance shifts the dynamic. You’re no longer reacting to a buyer’s findings. You’re presenting a business that has already done the work.

Sell-side preparation also shortens the overall process, which matters when timing is a factor. Buyers lose confidence when due diligence drags on. A seller who responds to requests quickly and clearly signals that the business is well run.

Working With BPM for Due Diligence

BPM’s due diligence services support business owners through every stage of a sale, from early sell-side preparation and quality of earnings analysis to tax diligence support and deal structuring. We’ve seen what buyers look for and where deals get into trouble, and we help sellers get ahead of those issues before they affect negotiations.

If you’re considering a sale in the next one to three years, the time to start preparing is now. Contact BPM to talk with our transaction advisory team about how to get your business ready.