Earn-outs, explained

An earn-out is one of the more elegant ideas in deal structuring on paper, and one of the more common sources of post-closing conflict in practice. The idea is straightforward: instead of arguing to a standstill over whose forecast for the business is correct, buyer and seller agree to let the business’s actual future results settle the question, with part of the price contingent on performance the seller can no longer fully control. That last part — control shifting to the buyer at exactly the moment the seller’s payout depends on results — is where nearly every earn-out dispute eventually traces back to.

What problem an earn-out is actually solving

Earn-outs typically appear where a buyer and seller have a genuine, good-faith disagreement about the business’s trajectory — a seller pointing to a new contract or product line just starting to ramp, a buyer reasonably reluctant to pay full price today for growth that has not yet actually happened. Rather than settling on a single number that satisfies neither side, an earn-out lets both be partly right: the buyer pays a lower amount at closing reflecting proven performance, and the seller receives additional payments later if the growth they promised actually materializes. Earn-outs also show up where a seller is staying involved with the business after closing, since tying part of their payout to results keeps their incentives aligned with the buyer’s during the handover.

Choosing what the earn-out is measured against

The metric an earn-out is calculated against shapes everything else about how it behaves, and the choice is not neutral. Revenue-based earn-outs are simple to measure and harder to manipulate through accounting choices, but they reward growth even if it comes at the cost of profitability, which can put a seller’s incentive at odds with the buyer’s actual interests. Earnings-based measures like EBITDA more closely track what the buyer actually cares about, but they are far more exposed to accounting judgment calls — how expenses are allocated, how overhead from the buyer’s other operations gets charged against the acquired business — which is exactly the kind of discretion a buyer now controls unilaterally. Whichever metric is chosen, the purchase agreement needs to define precisely how it is calculated, reported and audited, not leave the definition to be worked out once results start coming in.

Who runs the business during the earn-out period

This is the single most consequential question in any earn-out negotiation, and it is often under-negotiated relative to how much it matters. Once the deal closes, the buyer generally owns and controls the business, which means the buyer makes the day-to-day decisions — pricing, staffing, marketing spend, which product lines to push — that directly determine whether the earn-out metric is hit. A seller with no protection here is exposed to a buyer who, deliberately or simply through ordinary post-acquisition changes, runs the business in a way that suppresses the very number the seller’s payout depends on. Negotiated protections — operating covenants requiring the business to be run in the ordinary course, restrictions on diverting sales or shifting costs into the acquired business, minimum spending commitments on marketing or headcount — exist precisely to limit that exposure, and a seller accepting a meaningful earn-out without any of them is accepting far more risk than the headline number suggests.

Structuring the formula, the tiers and the caps

• A clear measurement period and reporting schedule, so both sides know exactly when and how performance gets calculated and disclosed.
• A defined formula, sometimes tiered so payments scale with results rather than triggering only above or below a single threshold.
• A cap on the maximum earn-out payment, giving the buyer certainty about its total exposure regardless of how well the business performs.
• A dispute mechanism specifying how a disagreement over the calculated metric actually gets resolved if the two sides cannot agree.

Where earn-out disputes actually come from

Disputes rarely start with an outright accusation of bad faith — they start with an ordinary post-acquisition decision that happens to affect the earn-out metric, made by a buyer who is simply running the business the way they would run any acquisition, without necessarily thinking about how it lands on the seller’s payout. A shared services allocation, a change in how a product line is priced, a decision to fold the acquired business into a larger sales team — any of these can plausibly suppress the earn-out number, and whether that was deliberate or incidental is exactly what the dispute ends up arguing about. This is why the operating covenants negotiated up front matter more than the formula itself in most real disputes; a precise formula applied to a business the seller had no ability to protect from ordinary interference solves the wrong problem.

What to negotiate on both sides of the table

A seller relying on a meaningful earn-out should negotiate real operating protections, reporting rights, and access to the financial detail needed to actually verify the calculation, not just the formula itself. A buyer, in turn, should push for a cap, a clear definition that does not tie their hands on legitimate post-acquisition decisions, and a defined process for resolving disagreements rather than an open-ended obligation to run the business exactly as the seller would have. Neither side benefits from an earn-out that reads well on the term sheet but was never built to survive the reality of one company running another company’s former business for a defined stretch of time.