M&A activity has entered a phase of measured resurgence, characterized less by volume and more by deal size, structural complexity, and execution risk. Following a prolonged slowdown caused by elevated interest rates, regulatory uncertainty, and valuation dislocation, the market stabilized in 2025 and rebounded meaningfully in the second half of the year. That recovery, however, has been uneven: global deal value has increased materially, driven primarily by megadeals, sponsor‑led take‑privates, and strategic transactions in technology, energy, and healthcare, while overall deal counts remain below historical norms. As private equity firms face mounting pressure in 2026 to deploy record levels of dry powder and exit long‑held assets and as financing conditions gradually improve- transactions are proceeding, but with heightened emphasis on downside protection, post‑closing adjustments, and risk allocation. In this environment, the legal architecture of the deal has become as important as the headline price, particularly given the growing incidence of post‑closing disputes.

Experience consistently demonstrates that many post‑M&A disputes are not the result of unforeseeable events, but rather predictable consequences of imprecision in transaction documents, insufficient integration of diligence findings, or misaligned assumptions regarding financial mechanics. Careful structuring and disciplined drafting at the front end of a transaction remain the most effective tools for mitigating post‑closing risk.

1. Drafting the SPA with Contractual Precision

Ambiguous drafting in sale and purchase agreements (SPAs) is among the most common drivers of post‑closing disputes. This risk is particularly pronounced where transactions employ a completion accounts mechanism under which the final purchase price is determined after closing.

Disputes frequently arise where the SPA fails to establish a clear hierarchy of applicable accounting standards, contractual accounting policies, and historical practices. Absent a well‑defined framework, the party preparing the completion accounts may exercise discretion in a manner that materially affects valuation outcomes. Similarly, imprecise definitions of “debt,” “cash,” or “working capital” often create disagreements as to whether specific items fall within the purchase price adjustment mechanics.

To mitigate these risks, SPAs should adopt prescriptive language wherever possible, minimize reliance on subjective standards, and expressly address areas requiring judgment. The inclusion of schedules containing illustrative calculations, account mappings, or pro forma examples can materially reduce interpretive risk and provide decision‑makers with practical guidance if disagreements arise.

2. Ensuring Diligence Findings Are Contractually Actionable

Financial due diligence is frequently treated as an informational exercise, rather than a mechanism for shaping contractual protection. As a result, buyers may identify material risks during diligence such as doubtful receivables, aggressive accounting practices, or contingent liabilities without ensuring those risks are adequately addressed in the SPA.

Where diligence identifies specific exposures, the agreement should reflect those findings through targeted indemnities, adjustments to reference metrics, or modifications to the purchase price mechanism. Without such protections, buyers may find themselves without contractual recourse when known risks materialize post‑closing.

Effective risk allocation further requires coordination across all diligence streams. Financial, legal, tax, and operational findings must be integrated into a cohesive transaction strategy, with clear channels for escalation and documentation. Fragmented diligence processes are a frequent precursor to post‑closing disagreement.

3. Addressing Financial Integrity and Information Risk

Post‑closing disputes often center on the reliability of financial information used to price the transaction or prepare completion accounts. In many cases, this arises from weaknesses in internal controls, unaudited financial statements, inconsistent accounting methodologies, or overly optimistic forecasts embedded in valuation models.

Buyers should carefully scrutinize accounting judgments that materially impact Earnings Before Interest, Taxes, Depreciation, and Amortization (EBITDA) or working capital, particularly where valuation is multiples‑based. Complex or opaque accounting practices may obscure liabilities, defer expenses, or accelerate revenue recognition in a manner that distorts underlying performance.

Where concerns remain following diligence, residual risk should be mitigated through appropriately tailored warranties and indemnities, complemented by clear contractual guidance governing the preparation of post‑closing financial statements. Generic accounting warranties are often insufficient, particularly in transactions involving smaller or less institutional sellers.

4. Managing Complexity in Contingent Consideration Structures

Earnouts, deferred consideration arrangements, and option mechanisms are increasingly common features of M&A transactions. While such tools can be effective in allocating risk and aligning incentives, they also generate a disproportionate share of post‑closing disputes.

Earnout disputes frequently arise where performance metrics are inadequately defined, where post‑closing operational control is not addressed, or where integration decisions materially affect the seller’s ability to achieve earnout thresholds. In many cases, the SPA contains extensive guidance for completion accounts but provides minimal direction for calculating contingent consideration.

To reduce dispute risk, parties should expressly address how extraordinary items, changes in business strategy, synergies, and buyer‑implemented cost controls will be treated for earnout purposes. Where complexity is unavoidable, clarity and internal consistency are essential.

5. Recognizing the Impact of Deal Dynamics

Transactional context plays a significant role in dispute risk. Time pressure, competitive auction processes, or strategic imperatives may incentivize parties to proceed despite unresolved issues. Once commercial momentum builds, there is often resistance to revisiting valuation assumptions or expanding contractual protections.

While such pressures may be unavoidable, best practices dictate early advisor involvement, disciplined scenario analysis, and clear internal decision‑making frameworks. Buyers, in particular, should remain receptive to diligence findings that challenge initial assumptions and ensure that identified risks are reflected in both pricing and documentation.

6. AI‑Related Risk

Transactions involving artificial intelligence, data‑driven tools, or algorithmic decision‑making introduce a distinct and growing category of post‑closing risk. Valuation assumptions tied to AI capabilities- whether embedded in forecasts, synergies, or earnout metrics may deteriorate if post‑closing performance fails to align with expectations. Disputes frequently arise where the SPA does not expressly address data ownership, lawful data sourcing, model governance, or the impact of post‑closing operational changes on contingent consideration. As AI‑enabled functions increasingly influence pricing, compliance, and revenue generation, failure to diligence and contract around AI‑related assets and risks is becoming a material source of post‑M&A disputes.

Conclusion

Post‑M&A disputes rarely arise from a single drafting defect or isolated diligence failure. They are more often the cumulative result of structural complexity, imprecise risk allocation, and assumptions that were never fully tested or memorialized in the transaction documents. In the current M&A environment marked by larger deals, increased reliance on post‑closing price adjustments, and expanding use of AI‑driven business models- the margin for error has narrowed considerably. Parties that invest early in integrated diligence, precise SPA drafting, and disciplined treatment of emerging risks such as AI and data governance are far better positioned to preserve deal value. As transactions continue to evolve in sophistication, clarity- both legal and commercial- remains the most effective tool for preventing disputes after the ink has dried.