A $4.2M deal almost fell apart at the closing table last quarter — not because of valuation, not because of financing, but because of a $340,000 disagreement over accounts receivable aging. Working capital adjustments are the silent deal-killers ofredactedAnd yet, most M&A practitioners still treat them as a last-minute checkbox rather than a negotiation battleground that deserves the same rigor as enterprise value itself. Here's the specific dynamic nobody talks about enough: The working capital peg — the agreed-upon 'normal' level of working capital a business should have at close — is almost always set using a trailing 12-month average. That sounds reasonable. But seasonal businesses, SaaS companies mid-billing-cycle, or any company that just landed a large contract will have a trailing average that flatters the seller and punishes the buyer. A broker I spoke with last month told me his team lost a $180,000 post-close adjustment dispute because their client's LOI defined working capital without explicitly excluding deferred revenue. The target was a software company. Deferred revenue was nearly $600,000 of the balance sheet. That's not a nuance — that's the whole game. The data backs up how widespread this is: according to SRS Acquiom's 2025 M&A Deal Terms Study, post-close working capital disputes were the single most common source of purchase price adjustment litigation, accounting for 61% of all adjustment claims filed. The median disputed amount? $1.1M. For deals under $50M, that's not rounding error — that's existential. Three things that actually move the needle on this: 1. Define 'current assets' and 'current liabilities' exhaustively in the LOI — not in the definitive agreement when leverage has already shifted. 2. Run a mock closing statement 30 days before close using real balance sheet data. Surprises at day 90 were visible at day 60 if anyone looked. 3. If the deal has seasonal revenue patterns, use a normalized monthly average pegged to the same calendar month as the expected close — not a blunt TTM figure. At AcquiAxis, we've been building tools that flag working capital peg anomalies automatically during diligence — comparing the proposed peg against historical seasonality curves and flagging deferred revenue, customer deposits, and accrued liabilities that are commonly misclassified. It doesn't eliminate the negotiation, but it makes sure your team walks in knowing exactly where the landmines are. The buyers who consistently win on working capital adjustments aren't the ones with the best lawyers at closing. They're the ones who started the conversation 60 days earlier with better data. What's the most unexpected working capital adjustment dispute you've seen derail — or nearly derail — a deal? Drop it in the comments. These stories are worth sharing.