Posted by Jennifer M. Settles, Esq. | July 15, 2026
Looking Under the Hood: The Due Diligence Red Flags That Kill Deals
Due diligence is the part of a deal where the buyer looks under the hood. After the handshake and the letter of intent, but before the money changes hands, the buyer’s team digs into the target’s finances, contracts, legal history, and operations to confirm that the business is what the seller says it is. It’s also where deals most often fall apart – not because buyers are looking for reasons to walk, but because diligence surfaces problems no one wanted to talk about earlier.
Whether you’re buying and want to know what to watch for, or selling and want to fix issues before they cost you, here are the red flags that most often derail a transaction, and what they signal.
Messy or Unreliable Financial Records
Nothing erodes a buyer’s confidence faster than financials that don’t add up. Books that are disorganized, inconsistent, or can’t be reconciled raise an obvious question: if the numbers you’re showing me are this shaky, what else is wrong? Even when there’s an innocent explanation, unreliable financials slow everything down and invite the buyer to lower their offer to account for the uncertainty. For sellers, clean, well-documented financials are the single best investment you can make before going to market.
Customer Concentration
If one or two customers account for a large share of revenue, that’s a flashing yellow light. The buyer immediately wonders what happens if that key customer leaves after closing, and whether they’re really buying a stable business or a small number of fragile relationships. Concentration doesn’t necessarily kill a deal, but it affects valuation and often leads buyers to push for protections like earnouts or holdbacks tied to whether those customers stay.
Contracts That Can’t Be Transferred
A buyer is purchasing the business’s relationships and agreements as much as its assets. So it’s a serious problem when key contracts (such as major customers, important suppliers, or the commercial lease) contain clauses requiring consent to transfer, or that let the other side terminate when the business is sold. Discovering at the last minute that the company’s most valuable contracts may not survive the transaction can stall or sink a deal. Identifying these early gives everyone time to seek the necessary consents.
Unclear Ownership of Assets or Equity
Buyers need to know that the seller actually owns what they’re selling. Ambiguity about who owns the equity, lingering claims from former partners or early investors, or intellectual property that turns out to be owned by a contractor rather than the company: all of these create real risk. A buyer can’t safely close when it’s unclear whether someone might later surface with a claim to the business or its key assets.
Pending or Threatened Litigation
Active lawsuits, threatened claims, or a history of recurring disputes give buyers serious pause. Beyond the direct cost and distraction, litigation hints at deeper issues – such as unhappy customers, employment problems, or sloppy practices. Undisclosed litigation is even worse: when a buyer discovers a claim the seller didn’t mention, it doesn’t just create a problem, it destroys trust in everything else the seller has represented.
Tax Problems and Unpaid Liabilities
Unpaid taxes, questionable tax positions, or undisclosed debts are classic deal-killers, in part because some liabilities can follow the business to a new owner. Buyers and their advisors look closely at whether all taxes have been paid and filed correctly and whether there are obligations lurking off the balance sheet. Surprises here suggest the seller’s house isn’t in order and that the buyer may be inheriting more than they bargained for.
Employee and Compensation Issues
People problems surface in diligence too. Misclassified workers, unpaid wages or overtime, undocumented compensation promises, or the looming departure of key employees can all complicate a deal. A buyer is often counting on the team to stay and the business to keep running smoothly. Signs that key people may leave, or that the company has unaddressed employment-law exposure, directly affect both value and willingness to close.
Missing Corporate Records and Lax Formalities
When a company can’t produce its basic corporate records (including formation documents, operating agreement or bylaws, minutes, resolutions, and accurate ownership records) it signals a business that hasn’t been run carefully. Beyond the inconvenience, sloppy formalities can raise questions about whether prior decisions were properly authorized and whether liability protection is intact. Disorganization at this level makes buyers wonder what other corners were cut.
Regulatory and Compliance Gaps
Lapsed licenses, missing permits, or failure to comply with the rules governing the company’s industry are significant red flags. Depending on the business, a compliance gap can mean fines, forced remediation, or even the inability to operate until it’s fixed—costs and risks a buyer will either price in heavily or refuse to take on. Regulated businesses in particular need their compliance house in order before inviting scrutiny.
The Seller Who Won’t Share Information
Sometimes the biggest red flag isn’t a specific finding; rather, it’s the seller’s behavior. A seller who is slow to produce documents, evasive about certain topics, or defensive when questioned makes buyers nervous, and reasonably so. Diligence runs on trust and transparency. A cooperative seller who gets ahead of problems builds confidence; one who seems to be hiding something invites buyers to assume the worst and walk away.
For Sellers: Run Diligence on Yourself First
Here’s the most valuable takeaway if you’re the one selling. Every red flag above is far cheaper to fix on your own schedule than to have a buyer discover it. The strongest sellers conduct their own diligence months before going to market – cleaning up records, resolving disputes, securing consents, and documenting ownership – so that when the buyer’s team starts digging, there are no surprises. Problems you’ve already addressed can’t be used as leverage against you.
The Bottom Line
Deals rarely collapse over a single catastrophic discovery. More often they erode, one red flag at a time, until the buyer loses confidence or concludes the risk isn’t worth it. The themes are consistent: clean records, clear ownership, transferable contracts, no hidden liabilities, and a transparent seller. Whether you’re buying or selling, understanding what diligence will surface, and addressing it early, is what keeps a promising deal from dying on the table.
If you’re preparing to buy or sell a business, knowing what due diligence will uncover (and getting ahead of it!) can be the difference between a deal that closes and one that falls apart. Schedule a free consultation to talk through your transaction before issues have a chance to derail it. Contact us as www.jsettleslaw.com or (602) 617-3938.
About the Author Jennifer M. Settles makes business owners’ lives easier. With 25+ years structuring M&A deals, commercial contracts, corporate governance, and complex real estate transactions, including over two decades as lead in-house transactions counsel for major corporations, she brings big-firm firepower to the founders, dealmakers, and growing companies who need it most. Clients describe her as knowledgeable, refreshingly direct, and relentlessly focused on their best interests. Jennifer offers white-glove, direct-access service and transparent, predictable fees. Learn more or schedule a consultation.
