You have spent months courting the right buyer or target, negotiated a term sheet everyone is proud of, and then the deal quietly dies somewhere between the data room and the closing table. That is not a rare accident. Due diligence, not the negotiating table, is where most M&A transactions actually fail. Recent industry data shows non-quality-of-earnings findings and EBITDA discrepancies now rank among the top reasons deals collapse, and the share of deals undone by quality-of-earnings issues alone has more than doubled in two years. For deal teams, buyers and sellers across Poland, the wider CEE region and beyond, this matters because a failed diligence process rarely costs only time — it costs reputation, advisory fees and momentum, often while a competitor closes the gap. This article explains why deals unravel during diligence, what the numbers reveal about the most common failure points, and how a disciplined process, including selecting the right virtual data room polska teams increasingly rely on, keeps a transaction on track from the first document request through signing.
Why Due Diligence Is Where Deals Actually Die
Negotiation gets the headlines, but diligence is where assumptions meet evidence. The Axial Dead Deal Report, which examined 75 failed transactions in 2025, found that non-QoE diligence findings accounted for 25.3% of failures, while quality-of-earnings and EBITDA discrepancies accounted for another 21.3% — together the single largest cluster of causes. Perhaps most striking is the trajectory: QoE-related failures climbed from just 10.6% of dead deals in 2023 to 21.3% in 2025, a sign that buyers are scrutinizing earnings quality far more aggressively than they did even two years ago. For advisors on both sides of the table, this shift means the old assumption — that a clean letter of intent is most of the way to closing — no longer holds. The real test now happens after terms are agreed, when accountants, lawyers and operational specialists spend weeks pressure-testing every claim behind the numbers.
Quality-of-Earnings Discrepancies Are the Fastest-Growing Deal Killer
Quality-of-earnings reviews exist to answer one question: is the reported EBITDA real, repeatable and defensible? When a buyer’s QoE advisor finds inflated add-backs, one-time revenue booked as recurring, or working capital assumptions that do not hold up, trust in the entire financial narrative erodes. Sellers who have not stress-tested their own numbers before going to market are routinely caught off guard, and renegotiation attempts at that stage frequently fail rather than succeed.
Incomplete Target Information Still Trips Up Buy-Side Teams
Numbers are only half the story. A joint survey from SRS Acquiom and Mergermarket found that 40% of boutique advisory firms identified incomplete target-company information as the single biggest hurdle in their most recent buy-side deal. Scattered contracts, inconsistent financial statements across folders, and missing corporate records slow down review and invite doubt. This is precisely where deal teams searching virtual data room polska listings are usually comparing document organization, version control and local data residency, because a disorganized repository turns a routine request into a multi-week delay. When a buyer’s legal and financial advisors have to chase down missing contracts or reconcile mismatched spreadsheets from different departments, the resulting delay does more than slow the calendar — it quietly signals that the seller’s internal record-keeping may be weaker than the pitch deck suggested, which invites harder questions everywhere else in the process.
Operational and Cultural Red Flags That Surface Too Late
Financial scrutiny gets the most attention, but operational issues sink plenty of deals on their own. Buyers who dig past the headline financials routinely uncover patterns that were never flagged in early conversations, and by the time they surface, trust has already taken a hit. Common red flags include:
-
Lack of internal financial controls or segregation of duties
-
Heavy reliance on a single customer or supplier for a large share of revenue
-
Outdated technology infrastructure requiring near-term reinvestment
-
High employee turnover in key functions
-
Key employees who signal plans to leave shortly after closing
A Familiar Scenario in Mid-Market Transactions
Advisors across Central and Eastern Europe describe a recurring pattern: a seller enters exclusivity confident in a strong EBITDA story, only for the buyer’s diligence team to discover that one customer represents 40% of revenue and that the general manager, who holds most of the client relationships, has no retention agreement and is quietly interviewing elsewhere. Neither issue is fatal on its own, but together they change the buyer’s risk calculus, trigger a valuation renegotiation, and in many cases push the deal past the point either side is willing to continue. The lesson advisors repeat is simple: red flags discovered by the buyer cost far more than the same issues disclosed proactively by the seller.
Timing Pressure Compounds Diligence Problems
Diligence failures rarely happen in isolation from the calendar. This is one more reason a well-run virtual data room polska advisors recommend is worth setting up before exclusivity even starts, since a platform built for fast, structured review compresses the calendar rather than stretching it. Average M&A due diligence timelines now run around 203 days industry-wide, up 64% over the past decade, as deals have grown more complex and buyers demand deeper verification. At the same time, exclusivity periods have not stretched to match. In one dataset, private equity buyers walked away from transactions after an average of 106 days under exclusivity, suggesting that as review windows lengthen relative to the clock the deal was negotiated under, timing pressure compounds whatever diligence problems already exist. Teams rushing toward a deadline tend to skip verification steps they would otherwise insist on, and that is exactly when disorganized documentation or an unresolved red flag becomes the reason a buyer walks. Lengthening diligence windows also mean more opportunities for a competing bidder, a shift in market conditions, or an internal budget cycle to change the buyer’s appetite altogether, so every extra week of avoidable delay carries real deal risk, not just scheduling inconvenience.
How to Prevent Deals From Failing in Diligence
Most diligence failures are preventable with earlier preparation and a more disciplined process. The following steps consistently reduce the risk of a deal unraveling after letter-of-intent:
-
Begin document preparation and financial cleanup months before going to market, not after a term sheet is signed.
-
Commission an independent, sell-side quality-of-earnings review to catch EBITDA and working capital issues before a buyer does.
-
Centralize all corporate, financial, legal and commercial documents in one organized, permission-controlled repository.
-
Disclose known operational and customer-concentration risks early, with a mitigation plan attached.
-
Negotiate exclusivity periods that realistically match the complexity of the transaction and the diligence scope.
-
Assign a single point of accountability on the seller side to answer buyer requests quickly and consistently.
Choosing a Virtual Data Room Poland and CEE Deal Teams Can Rely On
Document organization is not a minor administrative detail; it is one of the clearest levers sellers control. A virtual data room polska businesses trust should meet EU data protection standards, support Polish and English documentation side by side, provide granular permissions and detailed activity logs, and offer local support during the compressed windows when buyers submit dozens of requests at once. Platforms that track which documents have been viewed, flag outstanding requests, and organize files into a logical index make it far easier for a seller’s team to demonstrate readiness rather than scramble to catch up. For cross-border transactions involving Polish targets or acquirers, choosing a provider with regional data residency options and bilingual support also reduces friction during translation-heavy review stages.
Beyond security and organization, the practical test of any platform is how it performs under pressure, in the final weeks when both sides are exchanging dozens of requests a day. A well-structured index, a searchable Q&A log, and audit trails that satisfy both internal compliance and external counsel all reduce the chance that a document gets lost, a deadline slips, or a question goes unanswered long enough to sour the buyer’s confidence.
Conclusion
Deals fail at diligence far more often than they fail at the negotiating table, and the data makes the pattern clear: earnings-quality discrepancies, incomplete information, unresolved operational red flags and compressed timelines are the recurring culprits. None of these are unavoidable. Sellers who prepare early, disclose proactively and organize their documentation in a dependable virtual data room polska buyers and sellers across the region can navigate with confidence are far less likely to watch a promising transaction unravel in its final stretch. Diligence will always be where a deal’s real risk gets tested, but with the right preparation, that test becomes a formality rather than a gamble.